Luteoloside suppresses proliferation and metastasis of hepatocellular carcinoma cells by inhibition of NLRP3 inflammasome

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.

Allopurinol abates hepatocellular carcinoma in rats via modulation of NLRP3 inflammasome and NF-κB pathway

The present research was performed to examine the possible capability of allopurinol to prevent developing hepatocellular carcinoma (HCC) and to explore the fundamental mechanisms that control the hepatoprotective effect considering the enormous impact of HCC on patients' quality of life. Male Sprague Dawely rats were given i.p. injection of thioacetamide (TAA) (200 mg/kg) twice a week for 16 weeks in order to induce HCC. The histological analysis and assessment of the serum levels of liver function indicators verified the development of HCC. Two regimens of allopurinol (100 mg/kg, p.o.) were used; the first involved giving it concurrently with TAA from week 13 to week 16, and the second regimen started from week 9 to week 16. Chronic TAA damage was associated with considerable overexpression of the profibrogenic cytokine TGF-β, degradation and nuclear translocation of NF-κB, which released a number of inflammatory mediators, and upregulation of the NLRP3/caspase1 pathway. Administration of allopurinol demonstrated considerable enhancements in liver function and oxidative balance. Moreover, pathological characteristics like cirrhosis, dysplastic changes, and HCC nodules were greatly diminished. Allopurinol via suppressing TGF-β expression, inhibiting NF-κB nuclear translocation, and restricting inflammatory NLRP3/caspase1/IL-1β pathway was able to protect against TAA-induced liver damage, and it could be a promising therapy for HCC.

A comprehensive review of phytochemistry, pharmacology and clinical application of Gentianae Macrophyllae Radix

Gentianae Macrophyllae Radix (GMR) is a traditional Chinese herb with the function of dispelling wind and dampness, and removing damp heat. Currently, it is reported in the literature that GMR mainly contains iridoids and secoiridoids, in addition to triterpenoids, flavonoids, lignans, steroids, alkaloids and other chemical components. Among them, iridoids and secoiridoids are the main active ingredients of GMR. Modern pharmacological studies have shown that GMR has pharmacological effects such as anti-inflammatory, anti-tumor, hepatoprotective, immunomodulatory and cardioprotective. In clinical practice, GMR is mainly used to treat rheumatoid arthritis, ulcerative colitis, stroke and other related diseases with good therapeutic effects. Currently, there are few literature reports on the GMR research progress. Therefore, this paper provides a review of the chemical composition, pharmacological activity and clinical applications of GMR to provide some scientific basis for the further development of plant resources.

Lonicerae Japonicae Flos with the homology of medicine and food: a review of active ingredients, anticancer mechanisms, pharmacokinetics, quality control, toxicity and applications

Lonicerae Japonicae Flos (LJF, called Jinyinhua in China), comes from the dried flower buds or flowers to be opened of Lonicera japonica Thunb. in the Lonicera family. It has a long history of medicinal use and has a wide range of application prospects. As modern research advances, an increasing number of scientific experiments have demonstrated the anticancer potential of LJF. However, there is a notable absence of systematic reports detailing the anti-tumor effects of LJF. This review integrates the principles of Traditional Chinese Medicine (TCM) with contemporary pharmacological techniques, drawing upon literature from authoritative databases such as PubMed, CNKI, and WanFang to conduct a comprehensive study of LJF. Notably, a total of 507 compounds have been isolated and characterized from the plant to date, which include volatile oils, organic acids, flavonoids, iridoids, triterpenes and triterpenoid saponins. Pharmacological studies have demonstrated that LJF extract, along with components such as chlorogenic acid, luteolin, rutin, luteoloside, hyperoside and isochlorogenic acid, exhibits potential anticancer activities. Consequently, we have conducted a comprehensive review and summary of the mechanisms of action and clinical applications of these components. Furthermore, we have detailed the pharmacokinetics, quality control, and toxicity of LJF, while also discussing its prospective applications in the fields of biomedicine and preventive healthcare. It is hoped that these studies will provide valuable reference for the clinical research, development, and application of LJF.

Dual roles of inflammatory programmed cell death in cancer: insights into pyroptosis and necroptosis

Programmed cell death (PCD) is essential for cellular homeostasis and defense against infections, with inflammatory forms like pyroptosis and necroptosis playing significant roles in cancer. Pyroptosis, mediated by caspases and gasdermin proteins, leads to cell lysis and inflammatory cytokine release. It has been implicated in various diseases, including cancer, where it can either suppress tumor growth or promote tumor progression through chronic inflammation. Necroptosis, involving RIPK1, RIPK3, and MLKL, serves as a backup mechanism when apoptosis is inhibited. In cancer, necroptosis can enhance immune responses or contribute to tumor progression. Both pathways have dual roles in cancer, acting as tumor suppressors or promoting a pro-tumorigenic environment depending on the context. This review explores the molecular mechanisms of pyroptosis and necroptosis, their roles in different cancers, and their potential as therapeutic targets. Understanding the context-dependent effects of these pathways is crucial for developing effective cancer therapies.

Tumor biomarkers for diagnosis, prognosis and targeted therapy

Tumor biomarkers, the substances which are produced by tumors or the body's responses to tumors during tumorigenesis and progression, have been demonstrated to possess critical and encouraging value in screening and early diagnosis, prognosis prediction, recurrence detection, and therapeutic efficacy monitoring of cancers. Over the past decades, continuous progress has been made in exploring and discovering novel, sensitive, specific, and accurate tumor biomarkers, which has significantly promoted personalized medicine and improved the outcomes of cancer patients, especially advances in molecular biology technologies developed for the detection of tumor biomarkers. Herein, we summarize the discovery and development of tumor biomarkers, including the history of tumor biomarkers, the conventional and innovative technologies used for biomarker discovery and detection, the classification of tumor biomarkers based on tissue origins, and the application of tumor biomarkers in clinical cancer management. In particular, we highlight the recent advancements in biomarker-based anticancer-targeted therapies which are emerging as breakthroughs and promising cancer therapeutic strategies. We also discuss limitations and challenges that need to be addressed and provide insights and perspectives to turn challenges into opportunities in this field. Collectively, the discovery and application of multiple tumor biomarkers emphasized in this review may provide guidance on improved precision medicine, broaden horizons in future research directions, and expedite the clinical classification of cancer patients according to their molecular biomarkers rather than organs of origin.

The role of inflammasome in chronic viral hepatitis

Infections of hepatotropic viruses cause a wide array of liver diseases including acute hepatitis, chronic hepatitis and the consequently developed cirrhosis and hepatocellular carcinoma (HCC). Among the five classical hepatotropic viruses, hepatitis B virus (HBV) and hepatitis C virus (HCV) usually infect human persistently and cause chronic hepatitis, leading to major troubles to humanity. Previous studies have revealed that several types of inflammasomes are involved in the infections of HBV and HCV. Here, we summarize the current knowledge about their roles in hepatitis B and C. NLRP3 inflammasome can be activated and regulated by HBV and HCV. It is found to exert antiviral function or mediates inflammatory response in viral infections depending on different experimental models. Besides NLRP3 inflammasome, IFI16 and AIM2 inflammasomes participate in the pathological process of hepatitis B, and NALP3 inflammasome may sense HCV infection in hepatocytes. The inflammasomes affect the pathological process of viral hepatitis through its downstream secretion of inflammatory cytokines interleukin-1β (IL-1β) and IL-18 or induction of pyroptosis resulting from cleaved gasdermin D (GSDMD). However, the roles of inflammasomes in different stages of viral infection remains mainly unclear. More proper experimental models of viral hepatitis should be developed for specific studies in future, so that we can understand more about the complexity of inflammasome regulation and multifunction of inflammasomes and their downstream effectors during HBV and HCV infections.

Potential Role of Dietary Phenolic Compounds in the Prevention and Treatment of Rheumatoid Arthritis: Current Reports

Rheumatoid arthritis (RA) is a complex illness with both hereditary and environmental components. Globally, in 2019, 18 million people had RA. RA is characterized by persistent inflammation of the synovial membrane that lines the joints, cartilage loss, and bone erosion. Phenolic molecules are the most prevalent secondary metabolites in plants, with a diverse spectrum of biological actions that benefit functional meals and nutraceuticals. These compounds have received a lot of attention recently because they have antioxidant, anti-inflammatory, immunomodulatory, and anti-rheumatoid activity by modulating tumor necrosis factor, mitogen-activated protein kinase, nuclear factor kappa-light-chain-enhancer of activated B cells, and c-Jun N-terminal kinases, as well as other preventative properties. This article discusses dietary polyphenols, their pharmacological properties, and innovative delivery technologies for the treatment of RA, with a focus on their possible biological activities. Nonetheless, commercialization of polyphenols may be achievable only after confirming their safety profile and completing successful clinical trials.

Cistanche phenylethanoid glycosides induce apoptosis and pyroptosis in T-cell lymphoma

Cistanche deserticola, known for its extensive history in Traditional Chinese Medicine (TCM), is valued for its therapeutic properties. Recent studies have identified its anticancer capabilities, yet the mechanisms underlying these properties remain to be fully elucidated. In this study, we determined that a mixture of four cistanche-derived phenylethanoid glycosides (CPhGs), echinacoside, acteoside, 2-acetylacteoside, and cistanoside A, which are among the main bioactive compounds in C. deserticola, eliminated T-cell lymphoma (TCL) cells by inducing apoptosis and pyroptosis in vitro and attenuated tumor growth in vivo in a xenograft mouse model. At the molecular level, these CPhGs elevated P53 by inhibiting the SIRT2-MDM2/P300 and PI3K/AKT carcinogenic axes and activating PTEN-Bax tumor-suppressing signaling. Moreover, CPhGs activated noncanonical and alternative pathways to trigger pyroptosis. Interestingly, CPhGs did not activate canonical NLRP3-caspase-1 pyroptotic signaling pathway; instead, CPhGs suppressed the inflammasome factor NLRP3 and the maturation of IL-1β. Treatment with a caspase-1/4 inhibitor and silencing of Gasdermin D (GSDMD) or Gasdermin E (GSDME) partially rescued CPhG-induced cell death. Conversely, forced expression of NLRP3 restored cell proliferation. In summary, our results indicate that CPhGs modulate multiple signaling pathways to achieve their anticancer properties and perform dual roles in pyroptosis and NLRP3-driven proliferation. This study offers experimental support for the potential application of CPhGs in the treatment of TCL.

Anti-inflammatory effect of luteoloside against methylglyoxal induced human dental pulp cells

PURPOSE

The aim of this study was to investigate whether luteoloside, a flavonoid, could protect human dental pulp cells (HDPCs) against inflammation and oxidative stress induced by methylglyoxal (MGO), one of the advanced glycated end products (AGE) substances.

METHODS

HDPCs were stimulated with MGO and treated with luteoloside. MTT assay was used to determine cell viability. Protein expression was measured via western blotting. Reactive oxygen species (ROS) were measured with a Muse Cell Analyzer. Alkaline phosphatase activity (ALP) and Alizarin red staining were used for mineralization assay.

RESULTS

Luteoloside down-regulated the expression of inflammatory molecules such as ICAM-1, VCAM-1, TNF-α, IL-1β, MMP-2, MMP-9, and COX-2 in MGO-induced HDPCs without showing any cytotoxicity. It attenuated ROS formation and enhanced osteogenic differentiation such as ALP activity and Alizarin red staining in MGO-induced HDPCs. Overall, luteoloside showed protective actions against inflammation and oxidative stress in HDPCs induced by MGO through its anti-inflammatory, anti-oxidative, and osteogenic activities by down-regulating p-JNK in the MAPK pathway.

CONCLUSION

These results suggest that luteoloside might be a potential adjunctive therapeutic agent for treating pulpal pathological conditions in patients with diabetes mellitus.

Eriodictyol inhibits the motility, angiogenesis and tumor growth of hepatocellular carcinoma via NLRP3 inflammasome inactivation

NLRP3 involves in the development of hepatocellular carcinoma (HCC). Eriodictyol has shown its inhibitory effect on HCC cell proliferation. However, the underlying mechanism of eriodictyol in HCC is still unclear. This study aimed to explore the effect of and mechanism of eriodictyol on HCC. In this study, compared with eriodictyol (0 μM) group, eriodictyol significantly suppressed HepG2 cells (eriodictyol of 25, 50 and 100 μM) and Huh-7 cells (eriodictyol of 50 and 100 μM) viability, invasion, tube formation, metastasis-related genes MMP3, MMP16 and angiogenesis regulator VEGFA expressions with IC50 of 45.63 μM and 78.26 μM in vitro, respectively. Besides, eriodictyol significantly repressed NLRP3 expression, and reduced the protein levels of NLRP3 inflammasome-related proteins, adapter protein ASC, caspase-1, interleukin (IL)-18, and IL-1β in HepG2 (eriodictyol of 25, 50 and 100 μM) and Huh-7 cells (eriodictyol of 50 and 100 μM), respectively. Meanwhile, compared with control group, NLRP3 overexpression reversed the anti-metastatic effects of 100 μM eriodictyol on HCC cells invasion, tube formation, and metastasis-related genes MMP3, MMP16 and angiogenesis regulator VEGFA expressions, whereas NLRP3 knockdown enhanced the anti-metastatic effects of 100 μM eriodictyol on HCC cells. In vivo, compared with control group, eriodictyol significantly reduced the tumor growth, liver damage, inhibited the activation of NLRP3 inflammasome, and improved liver function, whereas NLRP3 overexpressing neutralized the anti-tumor effects of eriodictyol and degraded liver function. Hence, eriodictyol inhibited HCC cell viability, motility, angiogenesis and tumor growth via NLRP3 inflammasome inactivation both in vitro and in vivo.

Potential Impact of Bioactive Compounds as NLRP3 Inflammasome Inhibitors: An Update

The inflammasome NLRP3 comprises a caspase recruitment domain, a pyrin domain containing receptor 3, an apoptosis-linked protein like a speck containing a procaspase-1, and an attached nucleotide domain leucine abundant repeat. There are a wide variety of stimuli that can activate the inflammasome NLRP3. When activated, the protein NLRP3 appoints the adapter protein ASC. Adapter ASC protein then recruits the procaspase-1 protein, which causes the procaspase- 1 protein to be cleaved and activated, which induces cytokines. At the same time, abnormal activation of inflammasome NLRP3 is associated with many diseases, such as diabetes, atherosclerosis, metabolic syndrome, cardiovascular and neurodegenerative diseases. As a result, a significant amount of effort has been put into comprehending the mechanisms behind its activation and looking for their specific inhibitors. In this review, we primarily focused on phytochemicals that inhibit the inflammasome NLRP3, as well as discuss the defects caused by NLRP3 signaling. We conducted an in-depth research review by searching for relevant articles in the Scopus, Google Scholar, and PubMed databases. By gathering information on phytochemical inhibitors that block NLRP3 inflammasome activation, a complicated balance between inflammasome activation or inhibition with NLRP3 as a key role was revealed in NLRP3-driven clinical situations.

MASLD and aspartame: are new studies in the horizon?

Fatty liver disease has been on the rise in the past few decades, and there is no hope that it will stop. The terminology change that has been recently proposed may not be sufficient to advocate for a reduction of steatogenic foods and a change in lifestyle. A course change may be supported by the recent labeling of aspartame sweetener as a possible carcinogenic compound by the International Association for Research on Cancer (IARC), an agency of the World Health Organization (WHO). Aspartame sweeteners and other edulcorating molecular compounds besides colorings may trigger liver cancer other than fatty liver disease, despite limited data supporting it. An essential bias in human cohort studies is indeed the exclusion of all confounding factors, which may be barely impossible for human studies. In this perspective, we suggest that the activation of the NOD-like receptor-enclosing protein 3 (NLRP3) inflammasome and the stimulation of the tumor suppression gene TP53 may be critical in the progression from fatty liver to liver inflammation and liver cancer. Aspartame reduces a transcriptional coactivator, precisely the peroxisomal proliferator-initiated receptor-γ (gamma) coactivator 1-α (alpha) (or PGC1α). This coactivator upregulates mitochondrial bioformation, oxidative phosphorylation, respiratory capacity, and fatty acid β-oxidation. Aspartame acts in this way, probably through the activation of TP53. These events have been accountable for the variations in the lipid outline in serum and total lipid storage as well as for the impairment of gluconeogenesis in the liver, as supported by the downregulation of the gluconeogenic enzymes in experimental animals, and may be relevant in humans as well.

Metabolome Profiling of Marrubium peregrinum L. and Marrubium friwaldskyanum Boiss Reveals Their Potential as Sources of Plant-Based Pharmaceuticals

Marrubium species have been used since ancient times as food additives and curative treatments. Their phytochemical composition and various pharmacological activities were the focus of a number of scientific investigations but no comprehensive metabolome profiling to identify the numerous primary and secondary metabolites has been performed so far. This study aimed to generate a comprehensive picture of the total metabolite content of two Marrubium species-M. peregrinum and M. friwaldskyanum-to provide detailed information about the main primary and secondary metabolites. In addition, the elemental composition was also evaluated. For this purpose, non-targeted metabolomic analyses were conducted using GC-MS, UPLC-MS/MS and ICP-MS approaches. Nearly 500 compounds and 12 elements were detected and described. The results showed a strong presence of phenolic acids, flavonoids and their glucosides, which are generally of great interest due to their various pharmacological activities. Furthermore, tissue-specific analyses for M. friwaldskyanum stem, leaves and flowers were carried out in order to outline the sources of potentially important bioactive molecules. The results generated from this study depict the Marrubium metabolome and reveal its dual scientific importance-from one side, providing information about the metabolites that is fundamental and vital for the survival of these species, and from the other side, defining the large diversity of secondary substances that are a potential source of phytotherapeutic agents.

BTN3A3 inhibits clear cell renal cell carcinoma progression by regulating the ROS/MAPK pathway via interacting with RPS3A

Butyrophilin subfamily 3 member A3 (BTN3A3) is a member of the immunoglobulin superfamily and functions as a tumor suppressor in multiple cancer types. Our study has revealed that in clear cell renal cell carcinoma (ccRCC), patients who express high levels of BTN3A3 experience longer survival times than those with lower expression. Further, we have observed that BTN3A3 inhibits the proliferation, migration, and invasion of ccRCC cells. Through the utilization of an immunoprecipitation assay followed by mass spectrometry, we have discovered that BTN3A3 binds directly to RPS3A. Knockdown of BTN3A3 led to increased cell proliferation, migration, and invasion. However, this effect was significantly reduced when RPS3A was simultaneously overexpressed. Previous reports have demonstrated that RPS3A positively regulates mitochondrial function and reactive oxygen species (ROS) levels. Our study has shown that overexpression of both BTN3A3 and RPS3A can increase cellular oxygen consumption rate (OCR) and ROS levels. Furthermore, we have observed that the addition of H2O2 can reverse the effects of BTN3A3 knockdown on cell proliferation and migration by increasing the cellular ROS level. ROS play a crucial role in regulating the MAPK pathway and tumor cell growth. To further explore this relationship, we examined RNA-Seq and immunoblotting data and found that BTN3A3 can negatively regulate the degree of activation of the MAPK signaling pathway. This finding suggests that the BTN3A3/RPS3A complex may regulate ccRCC progression by modulating MAPK pathways. Therefore, BTN3A3 could serve as both a prognostic marker and a potential therapeutic target for ccRCC patients.

Suppression of inflammation-induced lung cancer cells proliferation and metastasis by exiguaflavanone A and exiguaflavanone B from Sophora exigua root extract through NLRP3 inflammasome pathway inhibition

Objective: Non-small cell lung cancer (NSCLC) is recognized for its aggressive nature and propensity for high rates of metastasis. The NLRP3 inflammasome pathway plays a vital role in the progression of NSCLC. This study aimed to investigate the effects of S. exigua extract and its active compounds on NLRP3 regulation in NSCLC using an in vitro model. Methods: S. exigua was extracted using hexane, ethyl acetate and ethanol to obtain S. exigua hexane fraction (SE-Hex), S. exigua ethyl acetate fraction (SE-EA), and S. exigua ethanol fraction (SE-EtOH) respectively. The active compounds were identified using column chromatography and NMR analysis. A549 cells were primed with lipopolysaccharide (LPS) and adenosine triphosphate (ATP) for activated NLRP3 inflammasome. The anti-inflammatory properties were determined using ELISA assay. The anti-proliferation and anti-metastasis properties against LPS-ATP-induced A549 cells were determined by colony formation, cell cycle, wound healing, and trans-well migration and invasion assays. The inflammatory gene expressions and molecular mechanism were determined using RT-qPCR and Western blot analysis, respectively. Results: SE-EA exhibited the greatest anti-inflammation properties compared with other two fractions as evidenced by the significant inhibition of IL-1β, IL-18, and IL-6, cytokine productions from LPS-ATP-induced A549 cells in a dose-dependent manner (p < 0.05). The analysis of active compounds revealed exiguaflavanone A (EGF-A) and exiguaflavanone B (EGF-B) as the major compounds present in SE-EA. Then, SE-EA and its major compound were investigated for the anti-proliferation and anti-metastasis properties. It was found that SE-EA, EGF-A, and EGF-B could inhibit the proliferation of LPS-ATP-induced A549 cells through cell cycle arrest induction at the G0/G1 phase and reducing the expression of cell cycle regulator proteins. Furthermore, SE-EA and its major compounds dose-dependently suppressed migration and invasion of LPS-ATP-induced A549 cells. At the molecular level, SE-EA, EGF-A, and EGF-B significantly downregulated the mRNA expression of IL-1β, IL-18, IL-6, and NLRP3 in LPS-ATP-induced A549 cells. Regarding the mechanistic study, SE-EA, EGF-A, and EGF-B inhibited NLRP3 inflammasome activation through suppressing NLRP3, ASC, pro-caspase-1(p50 form), and cleaved-caspase-1(p20 form) expressions. Conclusion: Targeting NLRP3 inflammasome pathway holds promise as a therapeutic approach to counteract pro-tumorigenic inflammation and develop novel treatments for NSCLC.

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.

The 'speck'-tacular oversight of the NLRP3-pyroptosis pathway on gastrointestinal inflammatory diseases and tumorigenesis

The NLRP3 inflammasome is an intracellular sensor and an essential component of the innate immune system involved in danger recognition. An important hallmark of inflammasome activation is the formation of a single supramolecular punctum, known as a speck, per cell, which is the site where the pro-inflammatory cytokines IL-1β and IL-18 are converted into their bioactive form. Speck also provides the platform for gasdermin D protein activation, whose N-terminus domain perforates the plasma membrane, allowing the release of mature cytokines alongside with a highly inflammatory form of cell death, namely pyroptosis. Although controlled NLRP3 inflammasome-pyroptosis pathway activation preserves mucosal immunity homeostasis and contributes to host defense, a prolonged trigger is deleterious and could lead, in genetically predisposed subjects, to the onset of inflammatory bowel disease, including Crohn's disease and ulcerative colitis, as well as to gastrointestinal cancer. Experimental evidence shows that the NLRP3 inflammasome has both protective and pathogenic abilities. In this review we highlight the impact of the NLRP3-pyroptosis axis on the pathophysiology of the gastrointestinal tract at molecular level, focusing on newly discovered features bearing pro- and anti-inflammatory and neoplastic activity, and on targeted therapies tested in preclinical and clinical trials.

The role of novel programmed cell death in head and neck squamous cell carcinoma: from mechanisms to potential therapies

Head and neck squamous cell carcinoma (HNSCC) is a common oral cancer with poor prognosis and for which no targeted therapeutic strategies are currently available. Accumulating evidence has demonstrated that programmed cell death (PCD) is essential in the development of HNSCC as a second messenger. PCD can be categorized into numerous different subroutines: in addition to the two well-known types of apoptosis and autophagy, novel forms of programmed cell death (e.g., necroptosis, pyroptosis, ferroptosis, and NETosis) also serve as key alternatives in tumorigenesis. Cancer cells are not able to avoid all types of cell death simultaneously, since different cell death subroutines follow different regulatory pathways. Herein, we summarize the roles of novel programmed cell death in tumorigenesis and present our interpretations of the molecular mechanisms with a view to the development of further potential therapies.

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.

New Approach for the Identification of Isobaric and Isomeric Metabolites

The structural elucidation of metabolite molecules is important in many branches of the life sciences. However, the isomeric and isobaric complexity of metabolites makes their identification extremely challenging, and analytical standards are often required to confirm the presence of a particular compound in a sample. We present here an approach to overcome these challenges using high-resolution ion mobility spectrometry in combination with cryogenic vibrational spectroscopy for the rapid separation and identification of metabolite isomers and isobars. Ion mobility can separate isomeric metabolites in tens of milliseconds, and cryogenic IR spectroscopy provides highly structured IR fingerprints for unambiguous molecular identification. Moreover, our approach allows one to identify metabolite isomers automatically by comparing their IR fingerprints with those previously recorded in a database, obviating the need for a recurrent introduction of analytical standards. We demonstrate the principle of this approach by constructing a database composed of IR fingerprints of eight isomeric/isobaric metabolites and use it for the identification of these isomers present in mixtures. Moreover, we show how our fast IR fingerprinting technology allows to probe the IR fingerprints of molecules within just a few seconds as they elute from an LC column. This approach has the potential to greatly improve metabolomics workflows in terms of accuracy, speed, and cost.

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.

NLRP3 inflammasome-induced pyroptosis in digestive system tumors

Programmed cell death (PCD) refers to cell death in a manner that depends on specific genes encoding signals or activities. PCD includes apoptosis, pyroptosis, autophagy and necrosis (programmed necrosis). Among these mechanisms, pyroptosis is mediated by the gasdermin family and is accompanied by inflammatory and immune responses. When pathogens or other danger signals are detected, cytokine action and inflammasomes (cytoplasmic multiprotein complexes) lead to pyroptosis. The relationship between pyroptosis and cancer is complex and the effect of pyroptosis on cancer varies in different tissue and genetic backgrounds. On the one hand, pyroptosis can inhibit tumorigenesis and progression; on the other hand, pyroptosis, as a pro-inflammatory death, can promote tumor growth by creating a microenvironment suitable for tumor cell growth. Indeed, the NLRP3 inflammasome is known to mediate pyroptosis in digestive system tumors, such as gastric cancer, pancreatic ductal adenocarcinoma, gallbladder cancer, oral squamous cell carcinoma, esophageal squamous cell carcinoma, in which a pyroptosis-induced cellular inflammatory response inhibits tumor development. The same process occurs in hepatocellular carcinoma and some colorectal cancers. The current review summarizes mechanisms and pathways of pyroptosis, outlining the involvement of NLRP3 inflammasome-mediated pyroptosis in digestive system tumors.

In-vitro inhibition of NLRP3 inflammasome by 3,6-dihydroxyflavone (3,6-DHF): a therapeutic strategy for the treatment of chronic inflammatory and autoimmune diseases

Nucleotide-binding oligomerization domain (NOD)-like receptor family pyrin domain containing 3 (NLRP3) inflammasome complex has an important role in immune system and its abnormal activation is associated with the pathogenesis of various inflammatory and auto-immune diseases. The study reveals the anti-inflammatory effects of 3,6-dihydroxyflavone (3,6-DHF). Here, we aimed to determine the inhibitory effects of 3,6-DHF on NLRP3 inflammasome and its associated components, thereby determining the signaling pathways involved in the inhibition. Reactive oxygen species (ROS) and nitric oxide (NO) were quantified by chemiluminescence and Griess methods, respectively. Inflammatory cell model was induced in human leukemic monocytes (THP-1). mRNA levels were estimated through real-time RT-PCR, protein expressions were evaluated by protein slot blot and immunocytochemistry, MTT and alamar blue assays were employed for toxicity studies. The compound 3,6-DHF was found to be the potent inhibitor of NLRP3 inflammasome by targeting the molecules involve in its activation pathway. Anti-inflammatory effects were revealed by inhibition of ROS and NO, reduction in the transcription of caspase-1, ASC, IL-1β and TLR-4 was observed along with the marked inhibition of NLRP3, IL-18, NF-κB and pNF-κB at translational level. 3,6-DHF was non-toxic on normal human fibroblast (BJ) and THP-1 cells and, could be a potential therapeutic agent in NLRP3 inflammasome driven diseases.

A novel inflammasome-related gene nomogram predicts survival in hepatocellular carcinoma

Inflammasomes are closely associated with the progression of multiple cancers. We established an inflammasome-related gene (IRG)-based model to predict the survival of patients with hepatocellular carcinoma (HCC). The RNA-sequencing data and clinical information of HCC patients were downloaded from the cancer genome atlas-liver hepatocellular carcinoma database, and the differentially expressed inflammasome-related gene were screened. Seven prognostic differentially expressed inflammasome-related genes were identified by univariate Cox analysis and incorporated into the risk model using least absolute shrinkage and selection operator-Cox algorithm. The predictive accuracy of the risk model was evaluated through the Kaplan-Meier, receiver operating characteristic and Cox regression analyses. The performance of the model was verified in the International Cancer Genome Consortium-Liver Cancer - RIKEN, JP cohort. A nomogram was constructed to predict the 1-, 2-, 3- ,and 5-year survival of HCC patients, and its performance was evaluated using calibration curves. The significantly enriched gene ontology terms, Kyoto encyclopedia of genes and genomes pathways and infiltrating immune cell populations associated with the IRG model were also analyzed to explore of the potential molecular mechanisms and immunotherapeutic targets. An independent and highly accurate prognostic model consisting of 7 IRGs was established and verified in 2 independent HCC cohorts. The IRG model was significantly associated with cell division and cell cycle. In addition, the high-risk group was more likely to have greater infiltration of immune cells and higher expression of immune checkpoint-related genes compared to the low-risk group. An IRG-based model was established to predict 1-, 2-, 3-, and 5-year survival rate in individual HCC patients, which provides new insights into the role of inflammasomes in HCC.

NLRP3 inflammasome activation By 17β-estradiol is a potential therapeutic target in hepatocellular carcinoma treatment

Hepatocellular carcinoma (HCC) is one of the most common cancers worldwide, and it mostly arises as a consequence of persistent chronic inflammation. Recently, NLRP3 inflammasome has caught the attention of many research groups due to its involvement in different types of cancer. However, its direct role in HCC remains elusive. Our study aimed to evaluate the role of NLRP3 inflammasome and pyroptosis in HCC and to clarify the potential mechanism by which 17β-estradiol (E2) can be used as a protective factor against HCC. NLRP3, caspase-1 (CASP1) as well as gasdermin-D (GSDMD) mRNA expression levels were assessed in human HCC tissues and adjacent non-cancerous liver tissues. Also, HepG2 HCC cells were cultured and treated with E2, followed by detection of the mRNA levels of these three genes. Our results revealed that NLRP3, CASP1, and GSDMD mRNA expressions were significantly lower in HCC tissues than in controls, and this under-expression was closely correlated with advanced HCC stages and grades. In contrast, HepG2 HCC cells displayed significantly higher expression levels of NLRP3 inflammasome components and GSDMD in the two E2-treated groups compared to the untreated group. Also, NLRP3, CASP1, and GSDMD mRNA expression levels were positively correlated with each other. This study confirmed that lack of NLRP3 inflammasome is involved in HCC progression and 17β-estradiol-induced activation of NLRP3 inflammasome may be effective in HCC treatment as it inhibited tumor cell growth and proliferation by triggering CASP1-dependent pyroptosis in HCC cells.

The role of NLRP3 inflammasome in hepatocellular carcinoma

Inflammasomes play an important role in innate immunity. As a signal platform, they deal with the excessive pathogenic products and cellular products related to stress and injury. So far, the best studied and most characteristic inflammasome is the NLR-family pyrin domain-containing protein 3(NLRP3) inflammasome, which is composed of NLRP3, apoptosis associated speck like protein (ASC) and pro-caspase-1. The formation of NLRP3 inflammasome complexes results in the activation of caspase-1, the maturation of interleukin (IL)-1β and IL-18, and pyroptosis. Many studies have demonstrated that NLRP3 inflammasome not only participates in tumorigenesis, but also plays a protective role in some cancers. Hepatocellular carcinoma (HCC) is a major cause of cancer-related mortality. Currently, due to the lack of effective treatment methods for HCC, the therapeutic effect of HCC has not been ideal. Therefore, it is particularly urgent to explore the pathogenesis of HCC and find its effective treatment methods. The increasing evidences indicate that NLRP3 inflammasome plays a vital role in HCC, however, the related mechanisms are not fully understood. Hence, we focused on the recent progress about the role of NLRP3 inflammasome in HCC, and analyzed the relevant mechanisms in detail to provide reference for the future in-depth researches.

AIM2 upregulation promotes metastatic progression and PD-L1 expression in lung adenocarcinoma

Cancer metastasis leading to the dysfunction of invaded organs is the main cause of the reduced survival rates in lung cancer patients. However, the molecular mechanism for lung cancer metastasis remains unclear. Recently, the increased activity of inflammasome appeared to correlate with the metastatic progression and immunosuppressive ability of various cancer types. Our results showed that the mRNA levels of absence in melanoma 2 (AIM2), one of the inflammasome members, are extensively upregulated in primary tumors compared with normal tissues derived from the TCGA lung adenocarcinoma (LUAD) database. Moreover, Kaplan-Meier analysis demonstrated that a higher mRNA level of AIM2 refers to a poor prognosis in LUAD patients. Particularly, AIM2 upregulation is closely correlated with smoking history and the absence of EGFR/KRAS/ALK mutations in LUAD. We further showed that the endogenous mRNA levels of AIM2 are causally associated with the metastatic potentials of the tested LUAD cell lines. AIM2 knockdown suppressed but overexpression promoted the migration ability and lung colony-forming ability of tested LUAD cells. In addition, we found that AIM2 upregulation is closely associated with an increased level of immune checkpoint gene set, as well as programmed cell death-ligand 1 (PD-L1) transcript, in TCGA LUAD samples. AIM2 knockdown predominantly repressed but overexpression enhanced PD-L1 expression via altering the activity of PD-L1 transcriptional regulators NF-κB/STAT1 in LUAD cells. Our results not only provide a possible mechanism underlying the AIM2-promoted metastatic progression and immune evasion of LUAD but also offer a new strategy for combating metastatic/immunosuppressive LUAD via targeting AIM2 activity.

BTN3A3 inhibits the proliferation, migration and invasion of ovarian cancer cells by regulating ERK1/2 phosphorylation

Butyrophilin Subfamily 3 Member A3 (BTN3A3) is a type I transmembrane protein belonging to the immunoglobulin (Ig) superfamily, which is expressed in many cancers. Clinical data show that ovarian cancer patients with high expression of BTN3A3 have a longer survival time, but the mechanism of BTN3A3 in the occurrence and progression of ovarian cancer is still unclear. Here, we found that BTN3A3 knockdown can promote the proliferation, migration and invasion of ovarian cancer cells, while overexpression of BTN3A3 can inhibit the proliferation, migration and invasion of ovarian cancer cells. We analyzed the immunoprecipitated BTN3A3 complex by mass spectrometry and found that BTN3A3 binds to FGF2, and the overexpression of BTN3A3 leads to a decrease in the protein level of FGF2, which in turn leads to a decrease in the level of phosphorylation of ERK1/2. By increasing the protein level of FGF2, it was found that the level of ERK1/2 phosphorylation also increased. Finally, the cancer promotion phenomenon caused by BTN3A3 knockdown can be improved by using ERK1/2 inhibitor SCH772984. To sum up, BTN3A3 interacts with FGF2, which inhibits FGF2/ERK1/2 axis and ultimately inhibits the proliferation, migration and invasion of ovarian cancer cells. Our results suggest that BTN3A3 may be a prognostic marker and a potential therapeutic target for ovarian cancer.

Dual Role of Chitin as the Double Edged Sword in Controlling the NLRP3 Inflammasome Driven Gastrointestinal and Gynaecological Tumours

The role of NLRP3 in the tumour microenvironment is elusive. In some cancers, the activation of NLRP3 causes a worse prognosis and in some cancers, NLRP3 increases chances of survivability. However, in many cases where NLRP3 has a protumorigenic role, inhibition of NLRP3 would be a crucial step in therapy. Consequently, activation of NLRP3 would be of essence when inflammation is required. Although many ways of inhibiting and activating NLRP3 in cancers have been discussed before, not a lot of focus has been given to chitin and chitosan in this context. The availability of these marine compounds and their versatility in dealing with inflammation needs to be investigated further in relation with cancers, along with other natural extracts. In this review, the effects of NLRP3 on gastrointestinal and gynaecological cancers and the impact of different natural extracts on NLRP3s with special emphasis on chitin and chitosan is discussed. A research gap in using chitin derivatives as anti/pro-inflammatory agents in cancer treatment has been highlighted.

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.

Long Noncoding RNA and Circular RNA: Two Rising Stars in Regulating Epithelial-Mesenchymal Transition of Pancreatic Cancer

Pancreatic ductal adenocarcinoma (PDAC) is a highly malignant tumor with especially poor prognosis. However, the molecular mechanisms of pancreatic oncogenesis and malignant progression are not fully elucidated. Epithelial-mesenchymal transition (EMT) process is important to drive pancreatic carcinogenesis. Recently, long noncoding RNAs (lncRNAs) and circular RNAs(circRNAs) have been characterized to participate in EMT in PDAC, which can affect the migration and invasion of tumor cells by playing important roles in epigenetic processes, transcription, and post-transcriptional regulation. LncRNAs can act as competing endogenous RNAs (ceRNA) to sequester target microRNAs(miRNAs), bind to the genes which localize physically nearby, and directly interact with EMT-related proteins. Currently known circRNAs mostly regulate the EMT process in PDAC also by acting as a miRNA sponge, directly affecting the protein degradation process. Therefore, exploring the functions of lncRNAs and circRNAs in EMT during pancreatic cancer might help pancreatic cancer treatments.

Neutrophil Extracellular Traps (NETs) Promote Non-Small Cell Lung Cancer Metastasis by Suppressing lncRNA MIR503HG to Activate the NF-κB/NLRP3 Inflammasome Pathway

Neutrophil extracellular traps (NETs) that are produced in the tumour microenvironment (TME) have been suggested to play an essential role in the dissemination of metastatic cancer under multiple infectious and inflammatory conditions. However, the functions of NETs in promoting non-small cell lung cancer (NSCLC) metastasis and the underlying mechanisms remain incompletely understood. Here, we found that NETs promoted NSCLC cell invasion and migration by inducing epithelial to mesenchymal transition (EMT). To explore how NETs contribute to NSCLC metastasis, microarrays were performed to identify substantial numbers of long noncoding RNAs (lncRNAs) and mRNAs that were differentially expressed in NSCLC cells after stimulation with NETs. Interestingly, we observed that the expression of lncRNA MIR503HG was downregulated after NETs stimulation, and ectopic MIR503HG expression reversed the metastasis-promoting effect of NETs in vitro and in vivo. Notably, bioinformatics analysis revealed that differentially expressed genes were involved in the NOD-like receptor and NF-κB signalling pathways that are associated with inflammation. NETs facilitated EMT and thereby contributed to NSCLC metastasis by activating the NF-κB/NOD-like receptor protein 3 (NLRP3) signalling pathway. Further studies revealed that MIR503HG inhibited NETs-triggered NSCLC cell metastasis in an NF-κB/NLRP3-dependent manner, as overexpression of NF-κB or NLRP3 impaired the suppressive effect of MIR503HG on NETs-induced cancer cell metastasis. Together, these results show that NETs activate the NF-κB/NLRP3 pathway by downregulating MIR503HG expression to promote EMT and NSCLC metastasis. Targeting the formation of NETs may be a novel therapeutic strategy for treating NSCLC metastasis.

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.

Modulation of TLR/NF-κB/NLRP Signaling by Bioactive Phytocompounds: A Promising Strategy to Augment Cancer Chemotherapy and Immunotherapy

Background

Tumors often progress to a more aggressive phenotype to resist drugs. Multiple dysregulated pathways are behind this tumor behavior which is known as cancer chemoresistance. Thus, there is an emerging need to discover pivotal signaling pathways involved in the resistance to chemotherapeutic agents and cancer immunotherapy. Reports indicate the critical role of the toll-like receptor (TLR)/nuclear factor-κB (NF-κB)/Nod-like receptor pyrin domain-containing (NLRP) pathway in cancer initiation, progression, and development. Therefore, targeting TLR/NF-κB/NLRP signaling is a promising strategy to augment cancer chemotherapy and immunotherapy and to combat chemoresistance. Considering the potential of phytochemicals in the regulation of multiple dysregulated pathways during cancer initiation, promotion, and progression, such compounds could be suitable candidates against cancer chemoresistance.

Objectives

This is the first comprehensive and systematic review regarding the role of phytochemicals in the mitigation of chemoresistance by regulating the TLR/NF-κB/NLRP signaling pathway in chemotherapy and immunotherapy.

Methods

A comprehensive and systematic review was designed based on Web of Science, PubMed, Scopus, and Cochrane electronic databases. The Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines were followed to include papers on TLR/NF-κB/NLRP and chemotherapy/immunotherapy/chemoresistance by phytochemicals.

Results

Phytochemicals are promising multi-targeting candidates against the TLR/NF-κB/NLRP signaling pathway and interconnected mediators. Employing phenolic compounds, alkaloids, terpenoids, and sulfur compounds could be a promising strategy for managing cancer chemoresistance through the modulation of the TLR/NF-κB/NLRP signaling pathway. Novel delivery systems of phytochemicals in cancer chemotherapy/immunotherapy are also highlighted.

Conclusion

Targeting TLR/NF-κB/NLRP signaling with bioactive phytocompounds reverses chemoresistance and improves the outcome for chemotherapy and immunotherapy in both preclinical and clinical stages.

Cell Death in Hepatocellular Carcinoma: Pathogenesis and Therapeutic Opportunities

Simple Summary

The progression of liver tumors is highly influenced by the interactions between cancer cells and the surrounding environment, and, consequently, can determine whether the primary tumor regresses, metastasizes, or establishes micrometastases. In the context of liver cancer, cell death is a double-edged sword. On one hand, cell death promotes inflammation, fibrosis, and angiogenesis, which are tightly orchestrated by a variety of resident and infiltrating host cells. On the other hand, targeting cell death in advanced hepatocellular carcinoma could represent an attractive therapeutic approach for limiting tumor growth. Further studies are needed to investigate therapeutic strategies combining current chemotherapies with novel drugs targeting either cell death or the tumor microenvironment.

Abstract

Hepatocellular carcinoma (HCC) is the most prevalent primary liver cancer and the third leading cause of cancer death worldwide. Closely associated with liver inflammation and fibrosis, hepatocyte cell death is a common trigger for acute and chronic liver disease arising from different etiologies, including viral hepatitis, alcohol abuse, and fatty liver. In this review, we discuss the contribution of different types of cell death, including apoptosis, necroptosis, pyroptosis, or autophagy, to the progression of liver disease and the development of HCC. Interestingly, inflammasomes have recently emerged as pivotal innate sensors with a highly pathogenic role in various liver diseases. In this regard, an increased inflammatory response would act as a key element promoting a pro-oncogenic microenvironment that may result not only in tumor growth, but also in the formation of a premetastatic niche. Importantly, nonparenchymal hepatic cells, such as liver sinusoidal endothelial cells, hepatic stellate cells, and hepatic macrophages, play an important role in establishing the tumor microenvironment, stimulating tumorigenesis by paracrine communication through cytokines and/or angiocrine factors. Finally, we update the potential therapeutic options to inhibit tumorigenesis, and we propose different mechanisms to consider in the tumor microenvironment field for HCC resolution.

Active Flavonoids From Lagotis brachystachya Attenuate Monosodium Urate-Induced Gouty Arthritis via Inhibiting TLR4/MyD88/NF-κB Pathway and NLRP3 Expression

Lagotis brachystachya Maxim is a characteristic herb commonly used in Tibetan medicine. Tibetan medicine records it as an important medicine for the clinical treatment of “Yellow Water Disease,” the symptoms of which are similar to that of arthritis. Our previous study showed that the flavonoid fraction extracted from L. brachystachya could attenuate hyperuricemia. However, the effects of the active flavonoids on gouty arthritis remain elusive, and the underlying mechanism is not understood. In the present study, the effects of the active flavonoids were evaluated in rats or Raw264.7 cells with gouty arthritis induced by monosodium urate (MSU) crystal, followed by the detection of TLR4, MyD88, pNF-κB, and NLR family pyrin domain-containing 3 (NLRP3) expression. The swelling of the ankle joint induced by MSU crystal began to be relieved 6 h post the administration with the active flavonoids. In addition, the active flavonoids not only alleviated MSU crystal-induced inflammation in synovial tissues by histopathological examination but also reduced tumor necrosis factor alpha (TNF-α) and interleukin-1 beta (IL-1β) levels in the joint tissue fluid of MSU crystal-induced rats. Furthermore, Western blot analysis indicated that the active flavonoids reduced the production of these cytokines by inhibiting the TLR4/MyD88/NF-κB pathway and decreasing NLRP3 expression in synovial tissues of rats. More importantly, the inhibition of TLR4/MyD88/NF-κB pathway and NLRP3 expression was also confirmed in MSU-induced Raw264.7 cells. In conclusion, these results indicated that the active flavonoids from L. brachystachya could effectively attenuate gouty arthritis induced by MSU crystal through the TLR4/MyD88/NF-κB pathway and NLRP3 expression in vivo and in vitro, suggesting several potential candidates for the treatment of gouty arthritis.

Effects of Cynaroside on Cell Proliferation, Apoptosis, Migration and Invasion though the MET/AKT/mTOR Axis in Gastric Cancer

The Chinese medicine monomer cynaroside (Cy) is a flavonoid glycoside compound that widely exists in plants and has a variety of pharmacological effects, such as its important role in the respiratory system, cardiovascular system and central nervous system. Studies have reported that Cy has varying degrees of anticancer activity in non-small cell lung cancer, cervical cancer, liver cancer, esophageal cancer and other cancers. However, there are no relevant reports about its role in gastric cancer. The MET/AKT/mTOR signaling pathway plays important roles in regulating various biological processes, including cell proliferation, apoptosis, autophagy, invasion and tumorigenesis. In this study, we confirmed that Cy can inhibit the cell growth, migration and invasion and tumorigenesis in gastric cancer. Our finding shows that Cy can block the MET/AKT/mTOR axis by decreasing the phosphorylation level of AKT, mTOR and P70S6K. Therefore, the MET/AKT/mTOR axis may be an important target for Cy. In summary, Cy has anti-cancer properties and is expected to be a potential drug for the treatment of gastric cancer.

Immunological and clinical immunotherapy implications of NLRP3 mutations in melanoma

Recent studies have demonstrated the role of Nod-like receptor protein 3 (NLRP3) inflammasome in promoting melanoma progression. Immune checkpoint inhibitors (ICI) treatment dramatically extended the survival outcomes for advanced melanoma patients. Nevertheless, immunologic and immunotherapy implications of NLRP3 mutations in melanoma were obscure. Herein, we utilized publicly genomic data of 750 melanoma patients to explore the association of NLRP3 mutations with immunologic and genomic features. In addition, we curated 336 advanced/metastatic melanoma patients treated with ICI agents from 6 published studies to analyze the response rate and survival outcome in relation to NLRP3 mutations. We observed that patients with NLRP3 mutations had a significantly higher tumor mutation burden (P < 0.001) and neoantigen burden (P < 0.001). Moreover, significantly lower tumor heterogeneity (P = 0.048) and purity (P = 0.022) were also observed in this mutated subgroup. Elevated infiltration of immune-response cells, decreased enrichment of immune-suppressive cells, and immune response-related circuits were markedly enriched in patients with NLRP3 mutations. In the pooled ICI-treated cohort, NLRP3 mutations were linked with the higher response rate (P = 0.031) and preferable survival outcome (P = 0.006). NLRP3 mutations were identified to associate with the elevated mutational burden, favorable immune infiltration, and preferable ICI efficacy. Findings derived from our study suggest that NLRP3 mutations may serve as a potential biomarker for evaluating melanoma immunotherapy response.

Active components from Lagotis brachystachya maintain uric acid homeostasis by inhibiting renal TLR4-NLRP3 signaling in hyperuricemic mice

Lagotis brachystachya Maxim is a herb widely used in traditional Tibetan medicine. Our previous study indicated that total extracts from Lagotis brachystachya could lower uric acid levels. This study aimed to further elucidate the active components (luteolin, luteoloside and apigenin) isolated from Lagotis brachystachya and the underlying mechanism in vitro and in vivo. The results showed that treatment with luteolin and luteoloside reversed the reduction of organic anion transporter 1 (OAT1) levels, while apigenin attenuated the elevation of urate transporter 1 (URAT1) and glucose transporter 9 (GLUT9) levels in uric acid-treated HK-2 cells, which was consistent with the finding in the kidneys of potassium oxonate (PO)-induced mice. On the other hand, hepatic xanthine oxidase activity was inhibited by the components. In addition, all of these active components improved the morphology of the kidney in hyperuricemic mice. Moreover, molecular docking showed that luteolin, luteoloside and apigenin could bind Toll-like receptor 4 (TLR4) and NLR family pyrin domain containing 3 (NLRP3). Congruently, western blot analysis showed that the components inhibited TLR4/myeloid differentiation primary response 88 (MyD88)/NLRP3 signaling. In conclusion, these results indicated that luteolin, luteoloside and apigenin could attenuate hyperuricemia by decreasing the production and increasing the excretion of uric acid, which were mediated by inhibiting inflammatory signaling pathways.

Hedyotis diffusa plus Scutellaria barbata Suppress the Growth of Non-Small-Cell Lung Cancer via NLRP3/NF-κB/MAPK Signaling Pathways

Hedyotis diffusa (HD) plus Scutellaria barbata (SB) have been widely used in antitumor clinical prescribes as one of herb pairs in China. We investigated the effect of aqueous extract from Hedyotis diffusa plus Scutellaria barbata at the equal weight ratio (HDSB11) in inhibiting the growth of murine non-small-cell lung cancer cell (NSCLC) line LLC in vivo and in vitro in this study. Compared with other aqueous extracts, HDSB11 showed the lowest IC₅₀ in inhibiting cell proliferation at 0.43 mg/ml. Besides, HDSB11 effectively suppressed colony formation and induced cell apoptosis. The further assessment of HDSB11 on the murine Lewis-lung-carcinoma-bearing mouse model showed it significantly inhibited tumors' bioluminescence at the dose of 30 g crude drug/kg. Mechanistically, HDSB11 attenuated the expressions of NLRP3, procaspase-1, caspase-1, PRAP, Bcl-2, and cyclin D1 and downregulated the phosphorylation levels of NF-κB, ERK, JNK, and p38 MAPK. In conclusion, HDSB11 could alleviate cell proliferation and colony formation and induce apoptosis in vitro and tumor growth in vivo, partly via NF-κB and MAPK signaling pathways to suppress NLRP3 expression.

Phytochemical inhibitors of the NLRP3 inflammasome for the treatment of inflammatory diseases

The NLRP3 inflammasome holds a crucial role in innate immune responses. Pathogen- and danger-associated molecular patterns may initiate inflammasome activation and following inflammatory cytokine release. The inflammasome formation and its-associated activity are involved in various pathological conditions such as cardiovascular, central nervous system, metabolic, renal, inflammatory and autoimmune diseases. Although the mechanism behind NLRP3-mediated disorders have not been entirely illuminated, many phytochemicals and medicinal plants have been described to prevent inflammatory disorders. In the present review, we mainly introduced phytochemicals inhibiting NLRP3 inflammasome in addition to NLRP3-mediated diseases. For this purpose, we performed a systematic literature search by screening PubMed, Scopus, and Google Scholar databases. By compiling the data of phytochemical inhibitors targeting NLRP3 inflammasome activation, a complex balance between inflammasome activation or inhibition with NLRP3 as central player was pointed out in NLRP3-driven pathological conditions. Phytochemicals represent potential therapeutic leads, enabling the generation of chemical derivatives with improved pharmacological features to treat NLRP3-mediated inflammatory diseases.

Targeting the NLRP3 Inflammasome as a New Therapeutic Option for Overcoming Cancer

Inflammasomes are multiprotein complexes that regulate the maturation and secretion of the proinflammatory cytokines interleukin-1beta (IL-1β and interleukin-18 (IL-18) in response to various intracellular stimuli. As a member of the inflammasomes family, NLRP3 is the most studied and best characterized inflammasome and has been shown to be involved in several pathologies. Recent findings have made it increasingly apparent that the NLRP3 inflammasome may also play a central role in tumorigenesis, and it has attracted attention as a potential anticancer therapy target. In this review, we discuss the role of NLRP3 in the development and progression of cancer, offering a detailed summary of NLRP3 inflammasome activation (and inhibition) in the pathogenesis of various forms of cancer. Moreover, we focus on the therapeutic potential of targeting NLRP3 for cancer therapy, emphasizing how understanding NLRP3 inflammasome-dependent cancer mechanisms might guide the development of new drugs that target the inflammatory response of tumor-associated cells.

Pyroptosis: mechanisms and diseases

Currently, pyroptosis has received more and more attention because of its association with innate immunity and disease. The research scope of pyroptosis has expanded with the discovery of the gasdermin family. A great deal of evidence shows that pyroptosis can affect the development of tumors. The relationship between pyroptosis and tumors is diverse in different tissues and genetic backgrounds. In this review, we provide basic knowledge of pyroptosis, explain the relationship between pyroptosis and tumors, and focus on the significance of pyroptosis in tumor treatment. In addition, we further summarize the possibility of pyroptosis as a potential tumor treatment strategy and describe the side effects of radiotherapy and chemotherapy caused by pyroptosis. In brief, pyroptosis is a double-edged sword for tumors. The rational use of this dual effect will help us further explore the formation and development of tumors, and provide ideas for patients to develop new drugs based on pyroptosis.

Genus Gentiana: A review on phytochemistry, pharmacology and molecular mechanism

ETHNOPHARMACOLOGICAL RELEVANCE

As the largest genus of Gentianaceae family, the Gentiana genus harbors over 400 species, widely distributed in the alpine areas of temperate regions worldwide. Plants from Gentiana genus are traditionally used to treat a wide variety of diseases including easing pain dispelling rheumatism, and treating liver jaundice, chronic pharyngitis and arthritis in China since ancient times. In this review, a systematic and constructive overview of the traditional uses, phytochemistry, molecular mechanisms, toxicology and pharmacological activities of the researched species of genus Gentiana is provided.

MATERIALS AND METHODS

The used information in this review is based on various databases (PubMed, Science Direct, Wiley online library, Wanfang Data, Web of Science) through a search using the keyword "Gentiana" in the period of 1981-2019. Besides, other ethnopharmacological information was acquired from Chinese herbal classic books and Chinese pharmacopoeia 2015 edition.

RESULTS

The plants from Gentiana genus have a long tradition of various medicinal uses in Europe and Asia. Phytochemical studies showed that the main bioactive components isolated from this genus includes iridoids xanthones and flavonoids. These compounds and extracts isolated from this genus show a wide range of protective activities including hepatic protection, gastrointestinal protection, cardiovascular protection, immunomodulation, joint protection, pulmonary protection, bone protection and reproductive protection. Molecular mechanism studies also indicated several potential therapeutic targets in the treatment of certain diseases by plants from this genus. Besides, natural products from this plant show no significant animal toxicity, cytotoxicity or genotoxicity.

CONCLUSION

This review summarized the traditional medicinal uses, phytochemistry, pharmacology, toxicology and molecular mechanism of genus Gentiana, providing references and research tendency for plant-based drug development and further clinical studies.

Galuteolin Inhibited Autophagy for Neuroprotection Against Transient Focal Cerebral Ischemia in Rats

Galuteolin, a Chinese herbal medicine, purified from Lonicera Japonica. In this study, we aimed to investigate the neuroprotective effect of galuteolin against cerebral ischemia/reperfusion (I/R) injury. We administered galuteolin or galuteolin and rapamycin to rats which had middle cerebral artery occlusion/reperfusion (MCAO/R). A series of characterizations were carried out to monitor the outcomes of galuteolin in I/R rats regarding the infarct volumes, neurological deficits, and brain water, as well as its effect on neuroprotection and autophagy. It was found that galuteolin significantly reduced the infarct volume, brain water content, and the neurological deficits in a dose-dependent manner. Neuron damages were decreased in the hippocampal carotid artery 1 pyramidal layer by galuteolin. The expression levels of neuron-specific enolase (NSE) increased after galuteolin treatment. Galuteolin significantly decreased the expression levels of autophagy-related proteins. In addition, galuteolin decreased rapamycin-related neuron damages and activations of autophagy in I/R rats. Our data suggested that galuteolin can inhibit ischemic brain injuries through the regulation of autophagy-related indicators in I/R.

Cynaroside protects human periodontal ligament cells from lipopolysaccharide-induced damage and inflammation through suppression of NF-κB activation

OBJECTIVE

To investigate whether cynaroside protects human periodontal ligament (hPDL) cells from lipopolysaccharide (LPS)-induced damage and inflammation and to analyze the underlying mechanism.

METHODS

LPS was used to stimulate hPDL and RAW264.7 cells. MTT assay was used to detect cell viability, and protein expression levels were measured via western blot analysis. Nitrite oxide and prostaglandin E₂ were used to quantify the inflammatory response. Alizarin Red S staining was used to detect mineralized nodules.

RESULTS

Cynaroside inhibited the expression of iNOS, COX-2, TNF-α, and IL-6 in LPS-stimulated hPDL and RAW264.7 cells without cytotoxicity. Furthermore, cynaroside significantly suppressed LPS-induced protein expression of matrix metalloproteinase 3. Additionally, cynaroside prevented LPS-induced NF-κB p65 subunit translocation to the nucleus by inhibiting the phosphorylation and degradation of IκB-α. Moreover, cynaroside could restore the mineralization ability of hPDL cells reduced by LPS.

CONCLUSION

Cynaroside protected hPDL cells from LPS-induced damage and inflammation via inhibition of NF-κB activation. These results suggest that cynaroside may be a potential therapeutic agent for the alleviation of periodontitis.

Discovery and Development of Inflammatory Inhibitors from 2-Phenylchromonone (Flavone) Scaffolds

Flavonoids are compounds based on a 2-phenylchromonone scaffold. Flavonoids can be divided into flavonoids, flavonols, dihydroflavones, anthocyanins, chalcones and diflavones according to the oxidation degree of the central tricarbonyl chain, the connection position of B-ring (2-or 3-position), and whether the tricarbonyl chain forms a ring or not. There are a variety of biological activities about flavonoids, such as anti-inflammatory activity, anti-oxidation and anti-tumor activity, and the antiinflammatory activity is apparent. This paper reviews the anti-inflammatory activities and mechanisms of flavonoids and their derivatives reported in China and abroad from 2011 till date (2011-2020), in order to find a good drug scaffold for the study of anti-inflammatory activities.

Immunomodulatory Effects of Diterpenes and Their Derivatives Through NLRP3 Inflammasome Pathway: A Review

Nucleotide-binding oligomerization domain-like receptor family pyrin domain-containing protein (NLRP) inflammasomes are involved in the molecular pathogenesis of many diseases and disorders. Among NLRPs, the NLRP3 (in humans encoded by the NLRP3 gene) is expressed predominantly in macrophages as a component of the inflammasome and is associated with many diseases, including gout, type 2 diabetes, multiple sclerosis, atherosclerosis, and neurological diseases and disorders. Diterpenes containing repeated isoprenoid units in their structure are a member of some essential oils that possess diverse biological activities and are becoming a landmark in the field of drug discovery and development. This review sketches a current scenario of diterpenes or their derivatives acting through NLRPs, especially NLRP3-associated pathways with anti-inflammatory effects. For this, a literature survey on the subject has been undertaken using a number of known databases with specific keywords. Findings from the aforementioned databases suggest that diterpenes and their derivatives can exert anti-inflammatory effects via NLRPs-related pathways. Andrographolide, triptolide, kaurenoic acid, carnosic acid, oridonin, teuvincenone F, and some derivatives of tanshinone IIA and phorbol have been found to act through NLRP3 inflammasome pathways. In conclusion, diterpenes and their derivatives could be one of the promising compounds for the treatment of NLRP3-mediated inflammatory diseases and disorders.