FNDC5 induces M2 macrophage polarization and promotes hepatocellular carcinoma cell growth by affecting the PPARγ/NF-κB/NLRP3 pathway

Mechanism and role of H. pylori CagA-induced NLRP3 inflammasome in gastric cancer immune cell infiltration

The high incidence of gastric cancer in China is strongly associated with widespread Helicobacter pylori infection. While the bacterium's role in gastric cancer initiation and progression is well-established, the precise molecular mechanisms remain incompletely characterized. Current clinical challenges include limited early detection methods and poor therapeutic efficacy in advanced stages. Immune checkpoint inhibitors have shown clinical benefits in subsets of patients; however, many exhibit primary resistance or acquire secondary resistance, though the mechanisms underlying this resistance remain poorly understood. Emerging evidence suggests that H.pylori infection may remodel the tumor microenvironment, thereby influencing gastric cancer pathogenesis, progression, and therapeutic response. This study investigates the CagA virulence factor-mediated signal-transduction pathway during H.pylori infection, elucidating its role in NLRP3 inflammasome activation and subsequent pathological modulation of gastric epithelial cells. We further analyze correlations between NLRP3 expression and clinicopathological features, evaluating its prognostic value in predicting clinical outcomes. Additionally, we examine how this signaling axis regulates immune cell infiltration and modulates molecular pathology within the tumor immune microenvironment, laying a foundation for novel diagnostic and immunotherapeutic strategies.

LncRNA MEG3 suppresses prostate cancer progression by mediating macrophage polarization via the miR-148a-3p/ARRDC3 signaling axis

Long-chain noncoding RNA (LncRNA) MEG3 significantly influences tumor microenvironment (TME) dynamics and macrophage polarization. However, its specific involvement in prostate cancer (PCa) progression remains unclear. MEG3 exhibited low expression in PCa, and immune infiltration analysis revealed a positive association with M1 macrophages infiltration and a negative association with M2 macrophages infiltration. Immunohistochemical analysis demonstrated increased MEG3 levels, corresponding with upregulated INOS (an M1 marker) and downregulated CD163 (an M2 marker). MEG3 expression was markedly elevated in LPS-induced M1 macrophages and notably reduced in IL-4-induced M2 macrophages. The overexpression of MEG3 significantly enhanced M1 macrophages polarization while suppressing M2 macrophages polarization. Using an online database and a dual luciferase reporter assay, miR-148a-3p was identified as a downstream target of MEG3. Reduced miR-148a-3p expression was observed in LPS-induced M1 macrophages, while an increase was noted in IL-4-induced M2 macrophages. Moreover, MEG3 overexpression's impact on macrophage polarization was nullified following miR-148a-3p mimic transfection. ARRDC3 was validated as a downstream target of miR-148a-3p. The upregulation of ARRDC3 triggered by MEG3 overexpression was effectively suppressed by miR-148a-3p mimics. Additionally, Knockdown of ARRDC3 effectively counteracted the MEG3 overexpression-induced increase in M1 macrophages polarization while simultaneously mitigating the reduction in M2 macrophages polarization. Collectively, MEG3 exhibits reduced expression in PCa and correlates with macrophage infiltration and polarization. Specifically, it drives M1 macrophages polarization while suppressing M2 macrophages polarization via the miR-148a-3p/ARRDC3 axis, thereby impeding tumor immune evasion and restricting PCa progression.

Perfluorohexanesulfonic Acid (PFHxS) Induces Hepatotoxicity through the PPAR Signaling Pathway in Larval Zebrafish (Danio rerio)

In recent years, the industrial substitution of long-chain per- and polyfluoroalkyl substances (PFAS) with short-chain alternatives has become increasingly prevalent, resulting in the widespread environmental detection of perfluorohexanesulfonic acid (PFHxS), a short-chain PFAS. However, there remains limited information about the potential adverse effects of PFHxS at environmental concentrations to wildlife. Here, early life stage zebrafish (Danio rerio) were exposed to environmentally relevant concentrations of PFHxS to better characterize the adverse effects of PFHxS on aquatic organisms. Nontargeted, transcriptomic analysis revealed potential hepatotoxic effects in exposed larvae, including macrovesicular and microvesicular hepatic steatosis, as well as focal liver necrosis. Morphological, histological, biochemical, and targeted transcript expression profiles further confirmed significant alterations in hepatocellular lesion numbers, liver pathological structures, relative liver size, liver biochemical parameters, and liver function genes. To validate the PPAR-mediated toxicological mechanism identified as an enriched pathway through in silico bioinformatics analysis, we tested the coexposure to an antagonist and PPAR morpholino knockdown. This intervention alleviated PFHxS-induced hepatic effects, including reductions in the levels of aspartate aminotransferase, alanine aminotransferase, total cholesterol, and total triglycerides. Our results demonstrate that environmentally relevant concentrations of PFHxS can impair liver development and function in fish, which could have potential risks to aquatic organisms.

The role of inflammasomes in hepatocellular carcinoma: Mechanisms and therapeutic insights

Hepatocellular carcinoma is among the most frequent forms of primary liver cancer and develops within a context of chronic inflammation, frequently associated with a multitude of risk factors, including viral infections, metabolic dysfunction-associated fatty liver disease, metabolic dysfunction-associated steatohepatitis and liver fibrosis. The tumor microenvironment is crucial for the progression of HCC, as immune cells, tumor-associated fibroblasts and hepatic stellate cells interact to promote chronic inflammation and tumor spread. Inflammasomes, the multiprotein complexes that launch the innate immune response, emerge as important mediators in the pathogenesis of HCC. Among others, the inflammasome Nucleotide-binding oligomerization domain, Leucine rich Repeat (NLR) and Pyrin (NLRP) 3 (NLRP3), and absent in melanoma 2 (AIM2), exhibit a dual role in HCC background. It has been reported that they can exert oncosuppressive functions by triggering the inflammatory death of cancer cells. Vice versa, chronic activation contributes to the development of a pro-tumorigenic environment, thus supporting tumor growth. In addition, other inflammasomes such as Nucleotide-binding oligomerization domain, Leucine rich Repeat (NLR) and Pyrin (NLRP) 6 and 12 (NLRP6 and NLRP12, respectively) regulate HCC onset and progression, although more experimental evidence is required. This review focuses on the molecular mechanisms underpinning the inflammasome's contribution to the onset, progression and spread of HCC. Moreover, we will explore the potential therapeutic approaches currently under investigation, which aim to improve the efficacy and reduce the side effects of the treatments currently available. Targeting inflammasomes may be a promising therapeutic strategy for the treatment of HCC, offering new opportunities to improve patient prognosis.

Mammary hydroxylated oestrogen activates the NLRP3 inflammasome in tumor-associated macrophages to promote breast cancer progression and metastasis

Breast cancer remains one of the primary causes of cancer-related death. An imbalance of oestrogen homeostasis and an inflammatory tumor microenvironment (TME) are vital risk factors for the progression and metastasis of breast cancer. Here, we showed that oestrogen homeostasis was disrupted both in breast cancer patients and in a transgenic MMTV-PyMT mouse model of breast cancer, and significant levels of hydroxylated oestrogen accumulated in the mammary tissues of these patients and mice. We also observed that tumor-associated macrophages (TAMs) were the main population of immune cells present in the breast TME. TAM-dependent tumor metastasis could be triggered by hydroxylated oestrogen via NLRP3 inflammasome activation and IL-1β production. Mechanistically, TAM-derived inflammatory cytokines induced the expression of matrix metalloproteinases (MMPs) in breast tumor cells, leading to breast tumor invasion and metastasis. Conceptually, our study reveals a previously unknown role of hydroxylated oestrogen in the reprogramming of the TME via NLRP3 inflammasome activation in TAMs, which ultimately facilitates breast cancer cells proliferation, migration, and invasion.

BIRC5 knockdown ameliorates hepatocellular carcinoma progression via regulating PPARγ pathway and cuproptosis

BACKGROUND

Hepatocellular carcinoma (HCC) with complex molecular carcinogenesis represents a kind of prevalent neoplasm occurring in the liver. The objective of this study is to illustrate the function of baculoviral inhibitor of apoptosis repeat containing 5 (BIRC5) and underlying action mechanisms in HCC progression.

METHODS

Comprehensive bioinformatics methods were conducted to screen differentially expressed genes (DEGs), cuproptosis-associated DEGs, and hub genes. The correlation between BIRC5 and immune cell infiltration, prognosis value was evaluated. The specific effects of BIRC5 silencing on HCC cells was validated by functional assays, and the impact on tumorigenicity and cuproptosis was also elucidated in vivo. Additionally, the effects of BIRC5 deficiency on PPAR pathway were determined using Oroxin A in vitro.

RESULTS

A total of 45 cuproptosis-associated DEGs and 9 hub genes were discovered through bioinformatics. Then 6 core genes were confirmed in Hep-3B and SK-Hep-1 cells with 4 genes upregulated and 2 genes downregulated. Therein, BIRC5 was positively correlated with the infiltration of CD8+ T cells, macrophages, and highly expressed BIRC5 exhibited poor prognosis of overall survival in HCC. Furthermore, BIRC5 deletion inhibited the PPARγ pathway, thereby restraining the malignant phenotypes of HCC cells and tumorigenesis in vivo. Additionally, silencing of BIRC5 contributed to the initiation of cuproptosis in HCC.

CONCLUSIONS

BIRC5 silencing attenuated HCC through blocking PPARγ pathway and regulating cuproptosis, which may offer therapeutic implications against HCC.

FNDC5 affects invasion and migration of oral cancer by inhibiting PI3K/Akt/Snail signaling pathway

This study first investigated how FNDC5 affected the development of oral cancer and revealed the role of FNDC5 in the migration and invasion of oral cancer. The present work evaluated differential FNDC5 expression within oral cancer samples versus matched non-carcinoma samples based on GEO database analysis and immunohistochemistry. We then generated oral cancer cell lines with FNDC5 overexpression and knockdown to determine the role of altered FNDC5 expression in the migration and invasion of oral cancer. PI3K inhibitor was used for investigating the possible mechanism underlying FNDC5 during EMT of oral cancer. Finally, these in-vitro results were validated using the lung metastatic nude mouse model. According to our results, FNDC5 level markedly decreased within oral cancer compared with adjacent samples and FNDC5 overexpression inhibited migration, invasion as well as EMT of oral cancer, while FNDC5 knockdown promoted oral cancer cell EMT. In addition, PI3K inhibitors blocked the induction of oral cancer cells EMT by FNDC5 knockdown. In vivo experiments further demonstrated the above results. This work is the first to illustrate the impact of FNDC5 on inhibiting migration and invasion of oral cancer, and our results suggest that FNDC5 affects EMT of oral cancer via the inhibition of PI3K/Akt/Snail pathway.

Identification of a novel PANoptosis-related gene signature for predicting the prognosis in clear cell renal cell carcinoma

PANoptosis has been shown to play an important role in tumorigenesis and gain more attention. Yet, the prognostic significance of PANoptosis-related genes has not been investigated more in clear cell renal cell carcinoma (ccRCC). The aim of this research was designed to identify and create a signature of PANoptosis-related genes which was expected to predict prognosis of ccRCC more effectively. The transcriptome data and clinical information were collected from The Cancer Genome Atlas database and the Gene Expression Omnibus database. Optimal differentially expressed PANoptosis-related genes, which were closely associated with prognosis and employed to construct a risk score, were extracted by univariate Cox analysis, least absolute shrinkage and selection operator Cox regression and multivariate Cox analysis. We performed Kaplan-Meier survival analysis and time-dependent receiver operating characteristic curves to complete this process. By adopting univariate and multivariate analysis, the constructed risk score was assessed to verify whether it could be taken as an independent contributor for prognosis. Moreover, we created a nomogram in order to predict overall survival (OS) of ccRCC. Five differentially expressed PANoptosis-related genes were screened out and used to construct a risk score. Our results showed that ccRCC patients with high risk score had a poor prognosis and shorter OS. The results of Kaplan-Meier curves and the area under the receiver operating characteristic curves of 1-, 3-, and 5-year OS indicated that the prediction performance was satisfactory. Additionally, the risk model could be taken as an independent prognostic factor in training and validation cohorts. The nomogram exhibited excellent reliability in predicting OS, which was validated by calibration curves. We identified 5 PANoptosis-related genes, which were used to construct a risk score and a nomogram for prognostic prediction with reliable predictive capability. The present study may provide new potential therapeutic targets and precise treatment strategies for ccRCC.

Comprehensive Analysis of the Mechanism of Anoikis in Hepatocellular Carcinoma

Background

Hepatocellular carcinoma (HCC), ranking as the second-leading cause of global mortality among malignancies, poses a substantial burden on public health worldwide. Anoikis, a type of programmed cell death, serves as a barrier against the dissemination of cancer cells to distant organs, thereby constraining the progression of cancer. Nevertheless, the mechanism of genes related to anoikis in HCC is yet to be elucidated.

Methods

This paper's data (TCGA-HCC) were retrieved from the database of the Cancer Genome Atlas (TCGA). Differential gene expression with prognostic implications for anoikis was identified by performing both the univariate Cox and differential expression analyses. Through unsupervised cluster analysis, we clustered the samples according to these DEGs. By employing the least absolute shrinkage and selection operator Cox regression analysis (CRA), a clinical predictive gene signature was generated from the DEGs. The Cell-Type Identification by Estimating Relative Subsets of RNA Transcripts (CIBERSORT) algorithm was used to determine the proportions of immune cell types. The external validation data (GSE76427) were procured from Gene Expression Omnibus (GEO) to verify the performance of the clinical prognosis gene signature. Western blotting and immunohistochemistry (IHC) analysis confirmed the expression of risk genes.

Results

In total, 23 prognostic DEGs were identified. Based on these 23 DEGs, the samples were categorized into four distinct subgroups (clusters 1, 2, 3, and 4). In addition, a clinical predictive gene signature was constructed utilizing ETV4, PBK, and SLC2A1. The gene signature efficiently distinguished individuals into two risk groups, specifically low and high, demonstrating markedly higher survival rates in the former group. Significant correlations were observed between the expression of these risk genes and a variety of immune cells. Moreover, the outcomes from the validation cohort analysis aligned consistently with those obtained from the training cohort analysis. The results of Western blotting and IHC showed that ETV4, PBK, and SLC2A1 were upregulated in HCC samples.

Conclusion

The outcomes of this paper underscore the effectiveness of the clinical prognostic gene signature, established utilizing anoikis-related genes, in accurately stratifying patients. This signature holds promise in advancing the development of personalized therapy for HCC.

Metabolic reprogramming in tumor immune microenvironment: Impact on immune cell function and therapeutic implications

Understanding of the metabolic reprogramming has revolutionized our insights into tumor progression and potential treatment. This review concentrates on the aberrant metabolic pathways in cancer cells within the tumor microenvironment (TME). Cancer cells differ from normal cells in their metabolic processing of glucose, amino acids, and lipids in order to adapt to heightened biosynthetic and energy needs. These metabolic shifts, which crucially alter lactic acid, amino acid and lipid metabolism, affect not only tumor cell proliferation but also TME dynamics. This review also explores the reprogramming of various immune cells in the TME. From a therapeutic standpoint, targeting these metabolic alterations represents a novel cancer treatment strategy. This review also discusses approaches targeting the regulation of metabolism of different nutrients in tumor cells and influencing the tumor microenvironment to enhance the immune response. In summary, this review summarizes metabolic reprogramming in cancer and its potential as a target for innovative therapeutic strategies, offering fresh perspectives on cancer treatment.

Biological impact and therapeutic implication of tumor-associated macrophages in hepatocellular carcinoma

The tumor microenvironment is a complex space comprised of normal, cancer and immune cells. The macrophages are considered as the most abundant immune cells in tumor microenvironment and their function in tumorigenesis is interesting. Macrophages can be present as M1 and M2 polarization that show anti-cancer and oncogenic activities, respectively. Tumor-associated macrophages (TAMs) mainly have M2 polarization and they increase tumorigenesis due to secretion of factors, cytokines and affecting molecular pathways. Hepatocellular carcinoma (HCC) is among predominant tumors of liver that in spite of understanding its pathogenesis, the role of tumor microenvironment in its progression still requires more attention. The presence of TAMs in HCC causes an increase in growth and invasion of HCC cells and one of the reasons is induction of glycolysis that such metabolic reprogramming makes HCC distinct from normal cells and promotes its malignancy. Since M2 polarization of TAMs stimulates tumorigenesis in HCC, molecular networks regulating M2 to M1 conversion have been highlighted and moreover, drugs and compounds with the ability of targeting TAMs and suppressing their M2 phenotypes or at least their tumorigenesis activity have been utilized. TAMs increase aggressive behavior and biological functions of HCC cells that can result in development of therapy resistance. Macrophages can provide cell-cell communication in HCC by secreting exosomes having various types of biomolecules that transfer among cells and change their activity. Finally, non-coding RNA transcripts can mainly affect polarization of TAMs in HCC.

Roles of peroxisome proliferator-activated receptors in hepatocellular carcinoma

Hepatocellular carcinoma (HCC), the main pathological type of liver cancer, is linked to risk factors such as viral hepatitis, alcohol intake and non-alcoholic fatty liver disease (NAFLD). Recent advances have greatly improved our understanding that NAFLD is playing a major risk factor for HCC. Peroxisome proliferator-activated receptors (PPARs) are a class of transcription factors divided into three subtypes: PPARα (PPARA), PPARδ/β (PPARD) and PPARγ (PPARG). As important nuclear receptors, PPARs are involved in many physiological processes, and PPARs can improve NAFLD by regulating lipid metabolism, accelerating fatty acid oxidation and inhibiting inflammation. In recent years, some studies have shown that PPARs can participate in the occurrence and development of HCC by regulating metabolic pathways. In addition, PPAR modulators have been reported to inhibit the proliferation and metastasis of HCC cells and can enhance the curative effect of conventional treatments. This article reviews the role of PPARs in the occurrence and development of HCC, as well as its value in the diagnosis, treatment and prognosis of HCC, in order to provide directions for future research.

Inhibitory effect and mechanism of Rosiglitazone on M1 type polarization of central microglia in intracerebral hemorrhage mice based on JNK/STAT3 signaling pathway

BACKGROUND

Intracerebral hemorrhage (ICH) seriously threatens the health of people. In addition, microglia M1 polarization was confirmed to be involved in the progression of ICH. Rosiglitazone was able to be used as an antidiabetic agent, which could activate PPAR-γ, and PPAR-γ was reported to inhibit inflammation in microglia. However, the detailed function of Rosiglitazone in ICH remains unclear.

METHODS

In vivo and in vitro experiments were used to test the function of Rosiglitazone in ICH. In addition, RT-qPCR and western blot were performed to evaluate the mRNA and protein level of PPAR-γ, respectively. Immunofluorescence staining was performed to detect the levels of CD206 and CD86, and ELISA was used to measure the levels of pro-inflammatory cytokines.

RESULTS

PPAR-γ was downregulated in ICH mice, whereas p-JNK and p-STAT3 were upregulated. Thrombin notably downregulated the level of PPAR-γ in BV2 cells, whereas Rosiglitazone partially reversed this phenomenon. In addition, Rosiglitazone markedly reversed thrombin-induced microglia M1 polarization. Consistently, thrombin-induced inflammatory response in BV2 cells was abolished in the presence of Rosiglitazone. SP600125 (JNK/STAT3 inhibitor) greatly reversed thrombin-induced M1 polarization in microglia, and GW9662 abolished the effect of SP600125. Meanwhile, Rosiglitazone could inactivate JNK/STAT3 pathway through the upregulation of PPAR-γ. Furthermore, Rosiglitazone notably alleviated the symptom of ICH in vivo through inhibiting the apoptosis and mediating PPAR-γ/JNK/STAT3 axis.

CONCLUSION

Rosiglitazone could attenuate the inflammation in ICH through inhibiting microglia M1 polarization. Thus, our research would shed now lights on exploring new therapeutic strategies against ICH.

NLRP3 inflammasome in hepatic diseases: A pharmacological target

The NOD-like receptor family pyrin domain containing 3 (NLRP3) inflammasome pathway is mainly responsible for the activation and release of a cascade of proinflammatory mediators that contribute to the development of hepatic diseases. During alcoholic liver disease development, the NLRP3 inflammasome pathway contributes to the maturation of caspase-1, interleukin (IL)-1β, and IL-18, which induce a robust inflammatory response, leading to fibrosis by inducing profibrogenic hepatic stellate cell (HSC) activation. Substantial evidence demonstrates that nonalcoholic fatty liver disease (NAFLD) progresses to nonalcoholic steatohepatitis (NASH) via NLRP3 inflammasome activation, ultimately leading to fibrosis and hepatocellular carcinoma (HCC). Activation of the NLRP3 inflammasome in NASH can be attributed to several factors, such as reactive oxygen species (ROS), gut dysbiosis, leaky gut, which allow triggers such as cardiolipin, cholesterol crystals, endoplasmic reticulum stress, and uric acid to reach the liver. Because inflammation triggers HSC activation, the NLRP3 inflammasome pathway performs a central function in fibrogenesis regardless of the etiology. Chronic hepatic activation of the NLRP3 inflammasome can ultimately lead to HCC; however, inflammation also plays a role in decreasing tumor growth. Some data indicate that NLRP3 inflammasome activation plays an important role in autoimmune hepatitis, but the evidence is scarce. Most researchers have reported that NLRP3 inflammasome activation is essential in liver injury induced by a variety of drugs and hepatotropic virus infection; however, few reports indicate that this pathway can play a beneficial role by inducing liver regeneration. Modulation of the NLRP3 inflammasome appears to be a suitable strategy to treat liver diseases.

Molecular characterization of ferroptosis in soft tissue sarcoma constructs a prognostic and immunotherapeutic signature through experimental and bioinformatics analyses

Ferroptosis regulators have been found to affect tumor progression. However, studies focusing on ferroptosis and soft tissue sarcoma (STS) are rare. Somatic mutation, copy number variation, reverse transcription-quantitative polymerase chain reaction (RT-qPCR) analysis, consensus clustering, differentially expressed genes analysis (DEGs), principal component analysis (PCA) and gene set enrichment analysis (GSEA) were used to identify and explore different ferroptosis modifications in STS. A nomogram was constructed to predict the prognosis of STS. Moreover, three immunotherapy datasets were used to assess the Fescore. Western blotting, siRNA transfection, EdU assay and reactive oxygen species (ROS) measurement were performed. 16 prognostic ferroptosis regulators were screened and significant differences were observed in somatic mutation, copy number variation (CNV) and RT-qPCR among these ferroptosis regulators. 2 different ferroptosis modification patterns were found (Fe cluster A and B). Fe cluster A with higher Fescore was correlated with p53 pathway and had better prognosis of STS (p = 0.002) while Fe cluster B with lower Fescore was correlated with angiogenesis and MYC pathway and showed a poorer outcome. Besides, the nomogram effectively predicted the outcome of STS and the Fescore could also well predict the prognosis of other 16 tumors and immunotherapy response. Downregulation of LOX also inhibited growth and increased ROS production in sarcoma cells. The molecular characterization of ferroptosis regulators in STS was explored and an Fescore was constructed. The Fescore quantified ferroptosis modification in STS patients and effectively predicted the prognosis of a variety of tumors, providing novel insights for precision medicine.

Trichinella spiralis dipeptidyl peptidase 1 suppressed macrophage cytotoxicity by promoting M2 polarization via the STAT6/PPARγ pathway

Trichinella spiralis dipeptidyl peptidase 1 (TsDPP1), or cysteine cathepsin C, is a secretory protein that is highly expressed during the infective larvae and adult worm stages in the intestines. The aim of this study was to investigate the mechanism by which recombinant TsDPP1 (rTsDPP1) activates macrophages M2 polarization and decreases macrophage cytotoxicity to kill newborn larvae via ADCC. RAW264.7 macrophages and murine peritoneal macrophages were used in this study. The results of the immunofluorescence test (IFT) and confocal microscopy showed that rTsDPP1 specifically bound to macrophages, and the binding site was localized on the cell membrane. rTsDPP1 activated macrophage M2 polarization, as demonstrated by high expression levels of Arg1 (M2 marker) and M2-related genes (IL-10, TGF-β, CD206 and Arg1) and high numbers of CD206+ macrophages. Furthermore, the expression levels of p-STAT6, STAT6 and PPARγ were obviously increased in rTsDPP1-treated macrophages, which were evidently abrogated by using a STAT6 inhibitor (AS1517499) and PPARγ antagonist (GW9662). The results indicated that rTsDPP1 promoted macrophage M2 polarization through the STAT6/PPARγ pathway. Griess reaction results revealed that rTsDPP1 suppressed LPS-induced NO production in macrophages. qPCR and flow cytometry results showed that rTsDPP1 downregulated the expression of FcγR I (CD64) in macrophages. The ability of ADCC to kill newborn larvae was significantly decreased in rTsDPP1-treated macrophages, but AS1517499 and GW9662 restored its killing capacity. Our results demonstrated that rTsDPP1 induced macrophage M2 polarization, upregulated the expression of anti-inflammatory cytokines, and inhibited macrophage-mediated ADCC via activation of the STAT6/PPARγ pathway, which is beneficial to the parasitism and immune evasion of this nematode.

LncRNA MEG3 Inhibits Tumor Progression by Modulating Macrophage Phenotypic Polarization via miR-145-5p/DAB2 Axis in Hepatocellular Carcinoma

Background

Hepatocellular carcinoma (HCC) is the predominant histological type of primary liver cancer, which ranks sixth among the most common human tumors. Tumor-associated macrophages (TAMs) are an important component of tumor microenvironment (TME) and the M2 macrophage polarization substantially contributes to tumor growth and metastasis. Long non-coding RNA (lncRNA) MEG3 was reported to restrain HCC development. However, whether MEG3 regulates macrophage phenotypic polarization in HCC remains unclear.

Methods

Bone marrow derived macrophages (BMDMs) were treated with LPS/IFNγ and IL4/IL13 to induce the M1 and M2 macrophage polarization, respectively. M2-polarized BMDMs were simultaneously transfected with adenovirus vector overexpressing MEG3 (Adv-MEG3). Subsequently, M2-polarized BMDMs were cultured for 24 h with serum-free medium, the supernatants of which were harvested as conditioned medium (CM). HCC cell line Huh7 was cultured with CM for 24 h. F4/80⁺CD68⁺ and F4/80⁺CD206⁺ cell percentages in M1-and M2-polarized BMDMs were calculated using flow cytometry. Huh7 cell migration, invasion and angiogenesis were determined via Transwell assay and tube formation experiment. Nude mice were implanted with Huh7 cells and Adv-MEG3-transfected M2-polarizd BMDMs, and tumor growth and M2 macrophage polarization markers were assessed. The binding between miR-145-5p and MEG3 or disabled-2 (DAB2) was verified by luciferase reporter assay.

Results

MEG3 presented lower expression in HCC tissues than in normal controls, and low expression of MEG3 was correlated to poorer prognosis of HCC patients. MEG3 expression was enhanced during LPS/IFNγ-induced M1 polarization, but was reduced during IL4/IL13-induced M2 polarization. MEG3 overexpression inhibited the expression of M2 polarization markers in both M2-polarized BMDMs and mice. Mechanically, MEG3 bound with miR-145-5p to regulate DAB2 expression. Overexpressing MEG3 suppressed M2 polarization-induced HCC cell metastasis and angiogenesis by upregulating DAB2 and inhibited in vivo tumor growth.

Conclusion

LncRNA MEG3 curbs HCC development by repressing M2 macrophage polarization via miR-145-5p/DAB2 axis.

NOD-like receptors in the pathogenesis of metabolic (dysfunction)-associated fatty liver disease: Therapeutic agents targeting NOD-like receptors

BACKGROUND AND AIMS

In metabolic (dysfunction)-associated fatty liver disease (MAFLD), activation of inflammatory processes marks the transition of simple steatosis to steatohepatitis, which can further evolve to advanced fibrosis or hepatocellular carcinoma. Under the stress of chronic overnutrition, the innate immune system orchestrates hepatic inflammation through pattern recognition receptors (PRRs). Cytosolic PRRs that include NOD-like receptors (NLRs) are crucial for inducing inflammatory processes in the liver.

METHODS

A literature search was performed with Medline (PubMed), Google Scholar and Scopus electronic databases till January 2023, using relevant keywords to extract studies describing the role of NLRs in the pathogenesis of MAFLD.

RESULTS

Several NLRs operate through the formation of inflammasomes, which are multimolecular complexes that generate pro-inflammatory cytokines and induce pyroptotic cell death. A multitude of pharmacological agents target NLRs and improve several aspects of MAFLD. In this review, we discuss the current concepts related to the role of NLRs in the pathogenesis of MAFLD and its complications. We also discuss the latest research on MAFLD therapeutics functioning through NLRs.

CONCLUSIONS

NLRs play a significant role in the pathogenesis of MAFLD and its consequences, especially through generation of inflammasomes, such as NLRP3 inflammasomes. Lifestyle changes (exercise, coffee consumption) and therapeutic agents (GLP-1 receptor agonists, sodium-glucose cotransporter-2 inhibitors, obeticholic acid) improve MAFLD and its complications partly through blockade of NLRP3 inflammasome activation. New studies are required to explore these inflammatory pathways fully for the treatment of MAFLD.

Polydatin ameliorates inflammation and oxidative stress associated with MSU-induced gouty arthritis in mice by regulating PPAR-γ and ferritin activation

AIMS

Polygonum cuspidatum Sieb. et Zucc is one of the commonly used herbs for the treatment of gouty arthritis, and polydatin is one of its main effective components. This study evaluated the therapeutic potential of polydatin for the treatment of gout.

MAIN METHODS

The ankle joint of C57BL/6 mice were injected with MSU suspensions to simulate human gouty arthritis, and oral treatment with polydatin (25, 50, and 100 mg/kg body weight) was performed at 1 h after MSU crystal injection. The effect of polydatin on model mice was evaluated by measuring ankle swelling, gait, histopathological analysis, proinflammatory cytokine expression, as well as the contents of NO, MDA and GSH. The targets of polydatin were explored by Real-Time PCR and IHC.

KEY FINDINGS

Treatment with polydatin inhibited ankle swelling, improved abnormal gait, and reduced ankle lesions dose-dependently. Moreover, polydatin decreased pro-inflammatory cytokine expression, and promoted expression of anti-inflammatory cytokine. In addition, polydatin inhibited MSU-induced oxidative stress by decreasing oxidative product (NO, MDA) generation and promote the antioxidant (GSH). Further, we found that polydatin reduced inflammation by decreasing the expression of NLRP3 inflammasome component via activating PPAR-γ. Moreover, polydatin can protect against iron overload and attenuate oxidative stress by promoting the activation of ferritin.

SIGNIFICANCE

Our findings indicates that polydatin ameliorates MSU-induced inflammation and oxidative stress by regulating PPAR-γ and ferritin activation in gouty arthritis model mice, and this research result suggests that polydatin has therapeutic potential for the treatment of gout in humans through multiple targets.

CYP2C19 Contributes to THP-1-Cell-Derived M2 Macrophage Polarization by Producing 11,12- and 14,15-Epoxyeicosatrienoic Acid, Agonists of the PPARγ Receptor

Although the functional roles of M1 and M2 macrophages in the immune response and drug resistance are important, the expression and role of cytochrome P450s (CYPs) in these cells remain largely unknown. Differential expression of the 12 most common CYPs (CYP1A1, 1A2, 1B1, 2B6, 2C8, 2C9, 2C19, 2D6, 2E1, 2J2, 3A4, and 3A5) were screened in THP-1-cell-derived M1 and M2 macrophages using reverse transcription PCR. CYP2C19 was highly expressed in THP-1-cell-derived M2 macrophages, but it was negligibly expressed in THP-1-cell-derived M1 macrophages at the mRNA and protein levels as analyzed by reverse transcription quantitative PCR and Western blot, respectively. CYP2C19 enzyme activity was also very high in THP-1-cell-derived M2 compared to M1 macrophages (> 99%, p < 0.01), which was verified using inhibitors of CYP2C19 activity. Endogenous levels of the CYP2C19 metabolites 11,12-epoxyeicosatrienoic acid (11,12-EET) and 14,15-EET were reduced by 40% and 50% in cells treated with the CYP2C19 inhibitor and by 50% and 60% in the culture medium, respectively. Both 11,12-EET and 14,15-EET were identified as PPARγ agonists in an in vitro assay. When THP-1-cell-derived M2 cells were treated with CYP2C19 inhibitors, 11,12- and 14,15-EETs were significantly reduced, and in parallel with the reduction of these CYP2C19 metabolites, the expression of M2 cell marker genes was also significantly decreased (p < 0.01). Therefore, it was suggested that CYP2C19 may contribute to M2 cell polarization by producing PPARγ agonists. Further studies are needed to understand the endogenous role of CYP2C19 in M2 macrophages with respect to immunologic function and cell polarization.

Role of NLRP3 inflammasome in hepatocellular carcinoma: A double-edged sword

In recent years, the study of NOD-like receptor thermal protein domain associated protein 3 (NLRP3) inflammasome has become a hot topic, especially its role in various tumors. The incidence of hepatocellular carcinoma is ranked in the top five in China. Hepatocellular carcinoma (HCC) is the predominant and typical form of primary liver cancer. Due to the close relationship between NLRP3 inflammasome and cancers, many studies have investigated its role in HCC. The results suggest that NLRP3 inflammasome participates in both tumor growth inhibition and tumor growth promotion in HCC. Therefore, this review elaborates on the relationship between NLRP3 and HCC and explains its role in HCC. In addition, the potential of NLRP3 as a therapeutic target for cancer therapy is explored, summarizing and classifying impacts of and processes underlying different NLRP3 inflammasome-targeting drugs on HCC.

The prognostic value of NLRP1/NLRP3 and its relationship with immune infiltration in human gastric cancer

BACKGROUND

Inflammasomes are related to tumorigenesis and immune-regulation. Here, we investigated the prognostic value of the NLR family pyrin domain containing (NLRP) 1/NLRP3 inflammasome and its potential mechanisms in immune-regulation in gastric cancer (GC).

METHODS

We analyzed the differential expression of NLRP1/NLRP3 between tumor and normal tissues using the Oncomine and Tumor Immune Estimate Resource (TIMER) databases. Immunohistochemistry and western blotting were used to detect NLRP1/NLRP3 protein expression in GC tissues. Correlations between NLRP1/NLRP3 expression levels and patient survival were analyzed using Kaplan-Meier survival curves. The relationships of NLRP1/NLRP3 expression and tumor-infiltrating immune cells/marker genes were assessed using the TIMER database. NLRP1/NLRP3 and immune checkpoint gene correlations were verified by single-gene co-expression analyses, and tumor immune-related pathways involving NLRP1/NLRP3 were analyzed using gene set enrichment analysis (GSEA).

RESULTS

Elevated NLRP1/NLRP3 expression was significantly correlated with lymph node metastasis, poor survival, immune-infiltrating cell abundances, and immune cell markers. NLRP3 showed stronger correlations with immune infiltration and the prognosis of gastric cancer. NLRP1 and NLRP3 might be involved in the same tumor immune-related pathways. Thus, high NLRP1/NLRP3 expression promotes immune cell infiltration and poor prognosis in GC. NLRP1/NLRP3, particularly NLRP3, may have important roles in immune infiltration and may serve as a prognostic biomarker for GC.

CONCLUSIONS

NLRP1/NLRP3, particularly NLRP3, may have important roles in immune infiltration and may serve as a prognostic biomarker for GC.

The Role of the NLRP3 Inflammasome in HCC Carcinogenesis and Treatment: Harnessing Innate Immunity

The HCC constitutes one of the most frequent cancers, with a non-decreasing trend in disease mortality despite advances in systemic therapy and surgery. This trend is fueled by the rise of an obesity wave which is prominent the Western populations and has reshaped the etiologic landscape of HCC. Interest in the nucleotide-binding domain leucine-rich repeat containing (NLR) family member NLRP3 has recently been revived since it would appear that, by generating inflammasomes, it participates in several physiologic processes and its dysfunction leads to disease. The NLRP3 inflammasome has been studied in depth, and its influence in HCC pathogenesis has been extensively documented during the past quinquennial. Since inflammation comprises a major regulator of carcinogenesis, it is of paramount importance an attempt to evaluate the contribution of the NLRP3 inflammasome to the generation and management of HCC. The aim of this review was to examine the literature in order to determine the impact of the NLRP3 inflammasome on, and present a hypothesis about its input in, HCC.

The potential role of FNDC5/irisin in various liver diseases: awakening the sleeping beauties

Fibronectin type III domain-containing protein 5 (FNDC5) is a transmembrane protein and the precursor of irisin, which serves as a systemic exerkine/myokine with multiple origins. Since its discovery in 2012, this hormone-like polypeptide has rapidly evolved to a component significantly involved in a gamut of metabolic dysregulations and various liver diseases. After a decade of extensive investigation on FNDC5/irisin, we are still surrounded by lots of open questions regarding its diagnostic and therapeutic values. In this review, we first concentrated on the structure-function relationship of FNDC5/irisin. Next, we comprehensively summarised the current knowledge and research findings regarding pathogenic roles/therapeutic applications of FNDC5/irisin in the context of non-alcoholic fatty liver disease, fibrosis, liver injury due to multiple detrimental insults, hepatic malignancy and intrahepatic cholestasis of pregnancy. Moreover, the prominent molecules involved in the underlying mechanisms and signalling pathways were highlighted. As a result, emerging evidence reveals FNDC5/irisin may act as a proxy for diagnosing liver disease pathology, a sensitive biomarker for assessing damage severity, a predisposing factor for surveilling illness progression and a treatment option with protective/preventive impact, all of which are highly dependent on disease grading and contextually pathological features.

IL-1 receptor-associated kinase 1 participates in the modulation of the NLRP3 inflammasome by tumor-associated macrophages in hepatocellular carcinoma

BACKGROUND

Hepatocellular carcinomas (HCCs) occur frequently in the digestive system and are associated with high mortality. This current study examined the regulatory relationship between interleukin (IL)-1 receptor-associated kinase 1 (IRAK1), NLR family pyrin domain-containing 3 (NLRP3) inflammasomes, and tumor-associated macrophages (TAMs) in the growth and metastasis of HCC.

METHODS

The expression of IRAK1 and NLRP3 was assessed in tissues and cells via quantitative real-time polymerase chain reaction (qRT-PCR) and Western blot analysis. Immunohistology was performed to detect the macrophage markers CD68, CD163, and CD168 in tumor tissues. Small interfering (si)RNA targeting IRAK1 (si-IRAK1) was designed to silence IRAK1 expression. Following si-IRAK1 transfection and/or co-culture with TAMs, HCC cell viability, proliferation, migration, and invasion, as well as the expression of NLRP3 and pro-inflammatory cytokines IL-1 β, IL-18, and monocyte chemotactic protein 1 (MCP-1) were assessed.

RESULTS

HCC tissues showed elevated expression of IRAK1 and NLRP3, as well as increased expression of the macrophage markers CD68, CD163, and CD168, compared to adjacent healthy tissues. Silencing of IRAK1 expression in HepG2 and Huh7 cells resulted in suppression of cell proliferation, migration, and invasion, and also reduced expression of NLRP3 and the pro-inflammatory cytokines IL-1β, IL-18, and MCP-1. Moreover, TAMs promoted HepG2 and Huh7 cell proliferation, migration, and invasion, and elevated the expression of NLRP3, IL-1β, IL-18, and MCP-1. Furthermore, IRAK1 silencing reversed the effects of TAMs on HepG2 and Huh7 cells.

CONCLUSIONS

The expression of IRAK1 was associated with HCC growth and metastasis, as well as NLRP3 inflammasome activation. The ability of TAMs to promote HCC growth and metastasis may be activated by NLRP3 inflammasomes and regulated by IRAK1.

Matrix stiffness regulates macrophage polarization in atherosclerosis

Atherosclerosis is a chronic inflammatory disease and the pathological basis of many fatal cardiovascular diseases. Macrophages, the main inflammatory cells in atherosclerotic plaque, have a paradox role in disease progression. In response to different microenvironments, macrophages mainly have two polarized directions: pro-inflammatory macrophages and anti-inflammatory macrophages. More and more evidence shows that macrophage is mechanosensitive and matrix stiffness regulate macrophage phenotypes in atherosclerosis. However, the molecular mechanism of matrix stiffness regulating macrophage polarization still lacks in-depth research, which hinders the development of new anti-atherosclerotic therapies. In this review, we discuss the important role of matrix stiffness in regulating macrophage polarization through mechanical signal transduction (Hippo, Piezo, cytoskeleton, and integrin) and epigenetic mechanisms (miRNA, DNA methylation, and histone). We hope to provide a new perspective for atherosclerosis therapy by targeting matrix stiffness and macrophage polarization.

FNDC5 Causes Resistance to Sorafenib by Activating the PI3K/Akt/Nrf2 Pathway in Hepatocellular Carcinoma Cells

In this study, we aimed to reveal the resistance mechanism of hepatocellular carcinoma (HCC) cells to sorafenib by exploring the effect of FNDC5 on sorafenib-induced ferroptosis in HCC cells. We compared the expression level of FNDC5 between sorafenib-resistant and sorafenib-sensitive HCC cell lines and the level of ferroptosis between the groups after treatment with sorafenib. We knocked down FNDC5 in drug-resistant cell lines and overexpressed it in sorafenib-sensitive HCC cell lines to further demonstrate the role of FNDC5 in sorafenib-induced ferroptosis. Using PI3K inhibitors, we revealed the specific mechanism by which FNDC5 functions. In addition, we verified our findings obtained in in vitro experiments using a subcutaneous tumorigenic nude mouse model. The findings revealed that FNDC5 inhibits sorafenib-induced ferroptosis in HCC cells. In addition, FNDC5 activated the PI3K/Akt pathway, which in turn promoted the nuclear translocation of Nrf2 and increased the intracellular antioxidant response, thereby conferring resistance to ferroptosis. Our study provides novel insights for improving the efficacy of sorafenib.