The anacardic 6-pentadecyl salicylic acid induces macrophage activation via the phosphorylation of ERK1/2, JNK, P38 kinases and NF-κB

Exploring the regulatory mechanism of intestinal flora based on PD-1 receptor/ligand targeted cancer immunotherapy

Serving as a pivotal immunotherapeutic approach against tumors, anti-PD-1/PD-L1 therapy amplifies the immune cells' capability to eliminate tumors by obstructing the interaction between PD-1 and PD-L1. Research indicates that immune checkpoint inhibitors are effective when a patient's gut harbors unique beneficial bacteria. As such, it has further been revealed that the gut microbiome influences tumor development and the efficacy of cancer treatments, with metabolites produced by the microbiome playing a regulatory role in the antitumor efficacy of Immune checkpoint inhibitors(ICBs). This article discusses the mechanism of anti-PD-1 immunotherapy and the role of intestinal flora in immune regulation. This review focuses on the modulation of intestinal flora in the context of PD-1 immunotherapy, which may offer a new avenue for combination therapy in tumor immunotherapy.

Gut microbiota: A double-edged sword in immune checkpoint blockade immunotherapy against tumors

Tumor cells can evade immune surveillance by expressing immune checkpoint molecule ligands, resulting in effective immune cell inactivation. Immune checkpoint blockades (ICBs) have dramatically improved survival of patients with multiple types of cancers. However, responses to ICB immunotherapy are heterogeneous with lower patient response rates. The advances have established that the gut microbiota can be as a promising target to overcome resistance to ICB immunotherapy. Furthermore, some bacterial species have shown to promote improved responses to ICBs. However, gut microbiota is critical in maintaining gut and systemic immune homeostasis. It not only promotes differentiation and function of immunosuppressive immune cells but also inhibits inflammatory cells via gut microbiota derived products such as short chain fatty acids (SCFAs), tryptophan (Trp) and bile acid (BA) metabolites, which play an important role in tumor immunity. Since the gut microbiota can either inhibit or enhance immune against tumor, it should be a double-edged sword in ICBs against tumor. In this review, we discuss the effects of gut microbiota on immune cells and also tumor cells, especially enhances of gut microbiota on ICB immunotherapy. These discussions can hopefully promote the development of ICB immunotherapy.

Quizartinib inhibits necroptosis by targeting receptor-interacting serine/threonine protein kinase 1

Systemic inflammatory response syndrome (SIRS), at least in part driven by necroptosis, is characterized by life-threatening multiple organ failure. Blocking the progression of SIRS and consequent multiple organ dysfunction is challenging. Receptor-interacting serine/threonine protein kinase 1 (RIPK1) is an important cell death and inflammatory mediator, making it a potential treatment target in several diseases. Here, using a drug repurposing approach, we show that inhibiting RIPK1 is also an effective treatment for SIRS. We performed cell-based high-throughput drug screening of an US Food and Drug Administration (FDA)-approved drug library that contains 1953 drugs to identify effective inhibitors of necroptotic cell death by SYTOX green staining. Dose-response validation of the top candidate, quizartinib, was conducted in two cell lines of HT-22 and MEFs. The effect of quizartinib on necroptosis-related proteins was evaluated using western blotting, immunoprecipitation, and an in vitro RIPK1 kinase assay. The in vivo effects of quizartinib were assessed in a murine tumor necrosis factor α (TNFα)-induced SIRS model. High-throughput screening identified quizartinib as the top "hit" in the compound library that rescued cells from necroptosis in vitro. Quizartinib inhibited necroptosis by directly inhibiting RIPK1 kinase activity and blocking downstream complex IIb formation. Furthermore, quizartinib protected mice against TNFα-induced SIRS. Quizartinib, as an FDA-approved drug with proven safety and efficacy, was repurposed for targeted inhibition of RIPK1. This work provides essential preclinical data for transferring quizartinib to the treatment of RIPK1-dependent necroptosis-induced inflammatory diseases, including SIRS.

Combined analysis of 16S rDNA sequencing and metabolomics to find biomarkers of drug-induced liver injury

Drug induced liver injury (DILI) is a kind of liver dysfunction which caused by drugs, and gut microbiota could affect liver injury. However, the relationship between gut microbiota and its metabolites in DILI patients is not clear. The total gut microbiota DNA was extracted from 28 DILI patient and 28 healthy control volunteers (HC) and 16S rDNA gene were amplified. Next, differentially metabolites were screened. Finally, the correlations between the diagnostic strains and differentially metabolites were studied.The richness and uniformity of the bacterial communities decreased in DILI patients, and the structure of gut microbiota changed obviously. Enterococcus and Veillonella which belong to Firmicutes increased in DILI, and Blautia and Ralstonia which belong to Firmicutes, Dialister which belongs to Proteobacteria increased in HC. In addition, these diagnostic OTUs of DILI were associated with the DILI damage mechanism. On the other hands, there were 66 differentially metabolites between DILI and HC samples, and these metabolites were mainly enriched in pyrimidine metabolism and steroid hormone biosynthesis pathways. Furthermore, the collinear network map of the key microbiota-metabolites were constructed and the results indicated that Cortodoxone, Prostaglandin I1, Bioyclo Prostaglandin E2 and Anacardic acid were positively correlated with Blautia and Ralstonia, and negatively correlated with Veillonella.This study analyzed the changes of DILI from the perspective of gut microbiota and metabolites. Key strains and differentially metabolites of DILI were screened and the correlations between them were studied. This study further illustrated the mechanism of DILI.

Advances in immunotherapy for triple-negative breast cancer

BACKGROUND

Immunotherapy has recently emerged as a treatment strategy which stimulates the human immune system to kill tumor cells. Tumor immunotherapy is based on immune editing, which enhances the antigenicity of tumor cells and increases the tumoricidal effect of immune cells. It also suppresses immunosuppressive molecules, activates or restores immune system function, enhances anti-tumor immune responses, and inhibits the growth f tumor cell. This offers the possibility of reducing mortality in triple-negative breast cancer (TNBC).

MAIN BODY

Immunotherapy approaches for TNBC have been diversified in recent years, with breakthroughs in the treatment of this entity. Research on immune checkpoint inhibitors (ICIs) has made it possible to identify different molecular subtypes and formulate individualized immunotherapy schedules. This review highlights the unique tumor microenvironment of TNBC and integrates and analyzes the advances in ICI therapy. It also discusses strategies for the combination of ICIs with chemotherapy, radiation therapy, targeted therapy, and emerging treatment methods such as nanotechnology, ribonucleic acid vaccines, and gene therapy. Currently, numerous ongoing or completed clinical trials are exploring the utilization of immunotherapy in conjunction with existing treatment modalities for TNBC. The objective of these investigations is to assess the effectiveness of various combined immunotherapy approaches and determine the most effective treatment regimens for patients with TNBC.

CONCLUSION

This review provides insights into the approaches used to overcome drug resistance in immunotherapy, and explores the directions of immunotherapy development in the treatment of TNBC.

Diet-gut microbial interactions influence cancer immunotherapy

The gut microbiome is involved in the absorption and metabolism of host nutrients and modulates the immune response, affecting the efficacy of immunotherapy for cancer. In patients receiving immunotherapy, appropriate modifications of gut microbiota are thought to improve therapeutic response. Of all the factors that influence the gut microbiota, diet is the most influential and modifiable. Healthy dietary patterns as well as some specific dietary components can help the growth of beneficial microbiota in the gut, thereby protecting against cancers and promoting human health. A growing number of researches have confirmed the positive effects of a diet-gut microbiota approach as an adjuvant therapy for cancer, but controversy remains. Here, we summarize the interactions between diet and gut microbes based on previous studies, and discuss the role of gut microbiota-based dietary strategies in tumor immunotherapy, with the potential mechanisms of actions also intensively discussed.

The mechanisms on evasion of anti-tumor immune responses in gastric cancer

The immune system and the tumor have been at each other's throats for so long that the neoplasm has learned to avoid detection and avoid being attacked, which is called immune evasion. Malignant tumors, such as gastric cancer (GC), share the ability to evade the body's immune system as a defining feature. Immune evasion includes alterations to tumor-associated antigens (TAAs), antigen presentation mechanisms (APMs), and the tumor microenvironment (TME). While TAA and APM are simpler in nature, they both involve mutations or epigenetic regulation of genes. The TME is comprised of numerous cell types, cytokines, chemokines and extracellular matrix, any one of which might be altered to have an effect on the surrounding ecosystem. The NF-kB, MAPK, PI3K/AKT, JAK/STAT, Wnt/β-catenin, Notch, Hippo and TGF-β/Smad signaling pathways are all associated with gastric cancer tumor immune evasion. In this review, we will delineate the functions of these pathways in immune evasion.

Computation-Assisted Identification of Bioactive Compounds in Botanical Extracts: A Case Study of Anti-Inflammatory Natural Products from Hops

The slow pace of discovery of bioactive natural products can be attributed to the difficulty in rapidly identifying them in complex mixtures such as plant extracts. To overcome these hurdles, we explored the utility of two machine learning techniques, i.e., Elastic Net and Random Forests, for identifying the individual anti-inflammatory principle(s) of an extract of the inflorescences of the hops (Humulus lupulus) containing hundreds of natural products. We fractionated a hop extract by column chromatography to obtain 40 impure fractions, determined their anti-inflammatory activity using a macrophage-based bioassay that measures inhibition of iNOS-mediated formation of nitric oxide, and characterized the chemical composition of the fractions by flow-injection HRAM mass spectrometry and LC-MS/MS. Among the top 10 predictors of bioactivity were prenylated flavonoids and humulones. The top Random Forests predictor of bioactivity, xanthohumol, was tested in pure form in the same bioassay to validate the predicted result (IC₅₀ 7 µM). Other predictors of bioactivity were identified by spectral similarity with known hop natural products using the Global Natural Products Social Networking (GNPS) algorithm. Our machine learning approach demonstrated that individual bioactive natural products can be identified without the need for extensive and repetitive bioassay-guided fractionation of a plant extract.

Amphipterygium adstringens (Schltdl.) Schiede ex Standl (Anacardiaceae): An Endemic Plant with Relevant Pharmacological Properties

Diseases, such as cancer, peptic ulcers, and diabetes, as well as those caused by drug-resistant infectious agents are examples of some of the world’s major public health problems. Amphipterygium adstringens (Schltdl.) Schiede ex Standl is an endemic tree to Mexico. Its stem bark has been used medicinally since pre-Hispanic times, but in recent decades it has been scientifically proven that it has properties that help counteract some diseases; extracts with organic solvents of the plant are outstanding for their anticancer, gastroprotective, and antimicrobial properties; terpenes and long-chain phenols have been identified as the main active compounds. Currently, overharvesting is causing a sharp reduction in natural populations due to an increase in demand for the stem bark by people seeking to improve their health and by national and transnational companies seeking to market it. Because of the growing interest of the world population and the scientific community, we reviewed recent studies on the bioactive properties of A. adstringens. Through the orderly and critical compendium of the current knowledge of A. adstringens, we provide a reference for future studies aimed at the rational use and protection of this valuable endemic natural resource.

Gut microbiota influence immunotherapy responses: mechanisms and therapeutic strategies

The gut microbiota have long been recognized to play a key role in human health and disease. Currently, several lines of evidence from preclinical to clinical research have gradually established that the gut microbiota can modulate antitumor immunity and affect the efficacy of cancer immunotherapies, especially immune checkpoint inhibitors (ICIs). Deciphering the underlying mechanisms reveals that the gut microbiota reprogram the immunity of the tumor microenvironment (TME) by engaging innate and/or adaptive immune cells. Notably, one of the primary modes by which the gut microbiota modulate antitumor immunity is by means of metabolites, which are small molecules that could spread from their initial location of the gut and impact local and systemic antitumor immune response to promote ICI efficiency. Mechanistic exploration provides novel insights for developing rational microbiota-based therapeutic strategies by manipulating gut microbiota, such as fecal microbiota transplantation (FMT), probiotics, engineered microbiomes, and specific microbial metabolites, to augment the efficacy of ICI and advance the age utilization of microbiota precision medicine.

Anacardic Acids from Amphipterygium adstringens Confer Cytoprotection against 5-Fluorouracil and Carboplatin Induced Blood Cell Toxicity While Increasing Antitumoral Activity and Survival in an Animal Model of Breast Cancer

Amphipterygium adstringens (cuachalalate) contains anacardic acids (AAs) such as 6-pentadecyl salicylic acid (6SA) that show immunomodulatory and antitumor activity with minimal or no secondary adverse effects. By contrast, most chemotherapeutic agents, such as 5-fluorouracil (5-FU) and carboplatin (CbPt), induce myelosuppression and leukopenia. Here, we investigated the myeloprotective and antineoplastic potential of an AA extract or the 6SA as monotherapy or in combination with commonly used chemotherapeutic agents (5-FU and CbPt) to determine the cytoprotective action of 6SA on immune cells. Treatment of Balb/c breast tumor-bearing female mice with an AA mixture or 6SA did not induce the myelosuppression or leukopenia observed with 5-FU and CbPt. The co-administration of AA mixture or isolated 6SA with 5-FU or CbPt reduced the apoptosis of circulating blood cells and bone marrow cells. Treatment of 4T1 breast tumor-bearing mice with the AA mixture or 6SA reduced tumor growth and lung metastasis and increased the survival rate compared with monotherapies. An increased effect was observed in tumor reduction with the combination of 6SA and CbPt. In conclusion, AAs have important myeloprotective and antineoplastic effects, and they can improve the efficiency of chemotherapeutics, thereby protecting the organism against the toxic effects of drugs such as 5-FU and CbPt.

Epigenetic Modifiers: Anti-Neoplastic Drugs With Immunomodulating Potential

Cancer cells are under the surveillance of the host immune system. Nevertheless, a number of immunosuppressive mechanisms allow tumors to escape protective responses and impose immune tolerance. Epigenetic alterations are central to cancer cell biology and cancer immune evasion. Accordingly, epigenetic modulating agents (EMAs) are being exploited as anti-neoplastic and immunomodulatory agents to restore immunological fitness. By simultaneously acting on cancer cells, e.g. by changing expression of tumor antigens, immune checkpoints, chemokines or innate defense pathways, and on immune cells, e.g. by remodeling the tumor stroma or enhancing effector cell functionality, EMAs can indeed overcome peripheral tolerance to transformed cells. Therefore, combinations of EMAs with chemo- or immunotherapy have become interesting strategies to fight cancer. Here we review several examples of epigenetic changes critical for immune cell functions and tumor-immune evasion and of the use of EMAs in promoting anti-tumor immunity. Finally, we provide our perspective on how EMAs could represent a game changer for combinatorial therapies and the clinical management of cancer.

New Insights Into the Cancer-Microbiome-Immune Axis: Decrypting a Decade of Discoveries

The past decade has witnessed groundbreaking advances in the field of microbiome research. An area where immense implications of the microbiome have been demonstrated is tumor biology. The microbiome affects tumor initiation and progression through direct effects on the tumor cells and indirectly through manipulation of the immune system. It can also determine response to cancer therapies and predict disease progression and survival. Modulation of the microbiome can be harnessed to potentiate the efficacy of immunotherapies and decrease their toxicity. In this review, we comprehensively dissect recent evidence regarding the interaction of the microbiome and anti-tumor immune machinery and outline the critical questions which need to be addressed as we further explore this dynamic colloquy.

Anacardic 6-pentadecyl salicylic acid induces apoptosis in breast cancer tumor cells, immunostimulation in the host and decreases blood toxic effects of taxol in an animal model

Many antineoplastic agents induce myelosuppression and leukopenia as secondary effects in patients. The development of anticancer agents that simultaneously provoke antitumor immune response represents an important therapeutic advance. The administration of 6-pentadecyl salicylic acid (6SA) contributes to the antitumor immunity using 4T1 breast cancer cells in Balb/c female mice, with Taxol as a positive control and in cotreatment with 6SA (6SA + Taxol; CoT). Our results show that 6SA reduces tumor volume and size by inducing caspase-8-mediated apoptosis without reducing tumor infiltrated lymphocytes. Also, 6SA reduced lung metastasis and increased the proportion of immune cells in blood, lymph nodes and bone marrow; more evidently, in the proportion of tumor-infiltrated natural killer (NK) cells and cytotoxic T lymphocytes. Taxol reduces helper and cytotoxic lymphocytes causing systemic immunosuppression and myelosuppression in bone marrow, whereas 6SA does not decrease any immune cell subpopulations in circulating blood and lymph nodes. More importantly, the CoT decreased the Taxol-induced cytotoxicity in circulating T cells and bone marrow. Treatment with 6SA increases the secretion of IL-2, IL-12, GM-CSF, TNF-α and IFN-γ and significantly reduces IL-10 and IL-17 secretion, suggesting that the reduction of regulatory T cells and tumor-associated macrophages contribute to the host control of tumor development. Finally, 6SA has an effective antineoplastic activity against breast cancer cells in an immunocompetent animal, reduces the myelosuppression and leukopenia that Taxol produces, improves the antitumoral immunological microenvironment and increases the overall survival of the animals improving the quality of life of patients with cancer.

Can the microbiota predict response to systemic cancer therapy, surgical outcomes, and survival? The answer is in the gut

INTRODUCTION

The gut microbiota seems to play a key role in tumorigenesis, across various hallmarks of cancer. Recent evidence suggests its potential use as a biomarker predicting drug response and adding prognostic information, generally in the context of immuno-oncology.

AREAS COVERED

In this review, we focus on the modulating effects of gut microbiota dysbiosis on various anticancer molecules used in practice, including cytotoxic and immune-modulating agents, primarily immune-checkpoint inhibitors (ICI). Pubmed/Medline-based literature search was conducted to find potential original studies that discuss gut microbiota as a prognostic and predictive biomarker for cancer therapy. We also looked at the US ClinicalTrials.gov website to find additional studies particularly ongoing human clinical trials.

EXPERT COMMENTARY

Sequencing of stool-derived materials and tissue samples from cancer patients and animal models has shown a significant enrichment of various bacteria such as Fusobacterium nucleatum and Bacteroides fragilis were associated with resistant disease and poorer outcomes. Gut microbiota was also found to be associated with surgical outcomes and seems to play a significant role in anastomotic leak (ATL) after surgery mainly by collagen breakdown. However, this research field is just at the beginning and the current findings are not yet ready to change clinical practice.

The antineoplastic agent anacardic 6-pentadecyl salicylic acid produces immunomodulation in vivo via the activation of MAPKs

Anacardic 6-pentadecyl salicylic acid (6SA) is the active component of Amphipterygium adstringens, a plant used in traditional medicine for the treatment of malaria and vascular diseases and as an anti-bacterial and immune-modulatory agent. However, the effect of 6SA on the immune system remains unclear. In this study, we examined the immune-stimulatory activity of 6SA in 6-8-week-old female BALB/c mice. We found that treatment with 2 mg/kg of 6SA increased the proportions of macrophages after 7 and 14 days of treatment and of natural killer (NK) cells after 14 days of treatment in circulating blood. In lymph nodes, treatment with 6SA for 14 days increased the number of macrophages. In addition, 6SA increases in the systemic levels of pro-inflammatory cytokines such as tumour necrosis factor (TNF)-α, interleukin (IL)-2, IL-12, IL-6 and IL-1β and of nitric oxide (NO). We observed an increase in the secretion of Granulocyte/Macrophage Colony Stimulation Factor (GM-CSF) that could explain the increase in the proportion of macrophages. Moreover, 6SA induced the classical activation of macrophages by increasing their expression of MHC-II and their production of TNF-α. These M1-polarised macrophages presented enhanced phagocytosis and NO secretion. This activation was due to induction of the phosphorylation of MAPKs such as ERK, JNK and p38 because specific inhibitors of the phosphorylation of these MAPKs reduced the 6SA-induced phagocytosis and NO and particularly, the secretion of GM-CSF in macrophages by inhibition of ERK. Despite these effects on macrophages, 6SA does not have any direct effect on the proportion of lymphocytes.

Regulation of p38MAPK-mediated dendritic cell functions by the deubiquitylase otubain 1

Dendritic cells (DCs) are professional antigen presenting cells (APCs) that represent the essential link between innate and acquired immunity. Otubain (OTUB) 1 is shown to deubiquitinate TRAFs to suppress virus-induced inflammatory response. MAPK, a downstream molecule of TRAFs, is involved in regulating LPS-induced immune reactions and its activation is sensitive to the presence of OTUB1. Little is known about contributions of OTUB1 to changes in biological properties of DCs. The present study, therefore, explored whether DC functions are influenced by OTUB1. To this end, DCs were isolated and cultured with GM-CSF to attain bone marrow-derived DCs (BMDCs) and followed by treatment with lipopolysaccharide (LPS) in the presence or absence of OTUB1 siRNA. Expression of markers of cellular maturation and proliferation were analyzed by flow cytometry, and secretion of inflammatory cytokines and ability to stimulate CD4⁺ T-cells in allogenic mixed leukocyte reaction (allo-MLR) by ELISA, cell migration by a transwell migration assay and phagocytic capacity by FITC-dextran uptake measurement. As a result, treatment of the cells with OTUB1 siRNA prolonged activation of p38MAPK, increased CD54 expression and IL-6 release and reduced FITC-dextran uptake. Moreover, cytokine release produced from CD4⁺ T-cells in allo-MLR was different. The enhanced level of IFN-γ, but not other cytokine production was observed in the presence of siRNA OTUB1. All the effects were completely abolished when the cells were exposed with p38MAPK inhibitor SB203580. In conclusion, OTUB1 prevents the prolonged activation of p38MAPK, which in turn compromises DC functions.

Curcumin reduces Ly6Chi monocyte infiltration to protect against liver fibrosis by inhibiting Kupffer cells activation to reduce chemokines secretion

Curcumin has been reported to have anti-fibrotic effect. However, the anti-fibrotic mechanism of curcumin for liver fibrosis remains obscure. In the presenting study, we aimed to investigate whether curcumin reduce chemokines secretion by inhibiting kupffer cells (KCs) activation to decrease Ly6C^hi monocyte infiltration in the treatment of liver fibrosis. Liver fibrosis was induced by intraperitoneal carbon tetrachloride (CCl₄)-injection in mice. Mice in curcumin group received curcumin treatment by gavage. Pretreatment with curcumin significantly protected mice from liver inflammation and fibrosis. Compared to CCl₄ group, mice in the curcumin group showed significantly less intrahepatic infiltration of Ly6C^hi monocytes, but no difference of other leucocyte subtypes. Moreover, curcumin significantly reduced Ly6C^hi monocytes associated pro-inflammatory and pro-fibrogenic cytokines, which was in line with the decreased numbers of intrahepatic Ly6C^hi monocytes. Further study found that curcumin is able to decrease KCs activation and monocyte chemokines, which explains why curcumin can reduce Ly6C^hi monocytes infiltration during liver fibrosis. In vitro, we discovered that curcumin prevents the polarization of macrophages toward M1 and reduces monocyte chemokines secretion, which is involved with ERK1/2 and p38 pathways. Taken together, for the first time, we verified that curcumin can reduce chemokines secretion by inhibiting KCs activation to decrease Ly6C^hi monocyte infiltration in the treatment of liver fibrosis. These results suggested that curcumin may be considered a promising candidate in the prevention and treatment of liver fibrosis.

Epigenetic control of macrophage polarization: implications for targeting tumor-associated macrophages

The progression of cancer is a result of not only the growth of the malignant cells but also the behavior of other components of the tumor microenvironment (TME). Tumor-associated macrophages (TAMs) are key components of the TME that influence tumor growth and disease progression. TAMs can either inhibit or support tumor growth depending on their polarization to classically-activated macrophages (M1s) or alternatively-activated macrophages (M2s), respectively. Epigenetic regulation plays a significant role in determining this polarization and manipulating the epigenetic regulation in macrophages would provide a means for selectively targeting M2s thereby eliminating tumor-supporting TAMs while sparing tumor-inhibiting M1 TAMs. Many pharmacologic modulators of epigenetic enzymes are currently used clinically and could be repurposed for treating tumors with high TAM infiltrate. While much research involving epigenetic enzymes and their modulators has been performed in M1s, significantly less is known about the epigenetic regulation of M2s. This review highlights the field’s current knowledge of key epigenetic enzymes and their pharmacologic modulators known to influence macrophage polarization.

Metagenomic Shotgun Sequencing and Unbiased Metabolomic Profiling Identify Specific Human Gut Microbiota and Metabolites Associated with Immune Checkpoint Therapy Efficacy in Melanoma Patients

This is the first prospective study of the effects of human gut microbiota and metabolites on immune checkpoint inhibitor (ICT) response in metastatic melanoma patients. Whereas many melanoma patients exhibit profound response to ICT, there are fewer options for patients failing ICT-particularly with BRAF-wild-type disease. In preclinical studies, specific gut microbiota promotes regression of melanoma in mice. We therefore conducted a study of the effects of pretreatment gut microbiota and metabolites on ICT Response Evaluation Criteria in Solid Tumors response in 39 metastatic melanoma patients treated with ipilimumab, nivolumab, ipilimumab plus nivolumab (IN), or pembrolizumab (P). IN yielded 67% responses and 8% stable disease; P achieved 23% responses and 23% stable disease. ICT responders for all types of therapies were enriched for Bacteroides caccae. Among IN responders, the gut microbiome was enriched for Faecalibacterium prausnitzii, Bacteroides thetaiotamicron, and Holdemania filiformis. Among P responders, the microbiome was enriched for Dorea formicogenerans. Unbiased shotgun metabolomics revealed high levels of anacardic acid in ICT responders. Based on these pilot studies, both additional confirmatory clinical studies and preclinical testing of these bacterial species and metabolites are warranted to confirm their ICT enhancing activity.

Silica nanoparticles inhibit macrophage activity and angiogenesis via VEGFR2-mediated MAPK signaling pathway in zebrafish embryos

The safety evaluation of silica nanoparticles (SiNPs) are getting great attention due to its widely-used in food sciences, chemical industry and biomedicine. However, the adverse effect and underlying mechanisms of SiNPs on cardiovascular system, especially on angiogenesis is still unclear. This study was aimed to illuminate the possible mechanisms of SiNPs on angiogenesis in zebrafish transgenic lines, Tg(fli-1:EGFP) and Albino. SiNPs caused the cardiovascular malformations in a dose-dependent manner via intravenous microinjection. The incidences of cardiovascular malformations were observed as: Pericardial edema > Bradycardia > Blood deficiency. The area of subintestinal vessels (SIVs) was significant reduced in SiNPs-treated groups, accompanied with the weaken expression of vascular endothelial cells in zebrafish embryos. Using neutral red staining, the quantitative number of macrophage was declined; whereas macrophage inhibition rate was elevated in a dose-dependent way. Furthermore, SiNPs significantly decreased the mRNA expression of macrophage activity related gene, macrophage migration inhibitory factor (MIF) and the angiogenesis related gene, vascular endothelial growth factor receptor 2 (VEGFR2). The protein levels of p-Erk1/2 and p-p38 MAPK were markedly decreased in zebrafish exposed to SiNPs. Our results implicate that SiNPs inhibited the macrophage activity and angiogenesis via the downregulation of MAPK singaling pathway.

Involvement of JNK signaling in IL4-induced M2 macrophage polarization

It has been generally accepted that alternatively activated macrophages (M2), which can be induced by type 2 cytokines such as IL-4, is responsible for tissue repair. However, the function of JNK in IL-4-induced M2 macrophage polarization remains unclear. Here, we demonstrated that M0 macrophages can be polarized into M2 status in response to IL-4 stimulation with the increased expression of the M2-specific molecular markers. We also found that IL-4 induced higher expression of JNK and transcription factor c-Myc in M2 macrophages. Our Q-PCR and Western blot results showed that JNK increased the expression of c-Myc and M2 markers Arg1, Mrc1. We also demonstrated c-Myc was the downstream of IL-4-JNK pathway. Further, the depletion of c-Myc, Arg1 and Mrc1 could inhibit the migration ability of M2 macrophages. Taken together, our data establishes a new role for JNK signaling in IL-4-induced alternative activation of macrophages and may provide a novel strategy for immune therapy.

Epigenetic Regulation of Interleukin 6 by Histone Acetylation in Macrophages and Its Role in Paraquat-Induced Pulmonary Fibrosis

Overexpression of interleukin 6 (IL-6) has been proposed to contribute to pulmonary fibrosis and other fibrotic diseases. However, the regulatory mechanisms and the role of IL-6 in fibrosis remain poorly understood. Epigenetics refers to alterations of gene expression without changes in the DNA sequence. Alternation of chromatin accessibility by histone acetylation acts as a critical epigenetic mechanism to regulate various gene transcriptions. The goal of this study was to determine the impact of IL-6 in paraquat (PQ)-induced pulmonary fibrosis and to explore whether the epigenetic regulations may play a role in transcriptional regulation of IL-6. In PQ-treated lungs and macrophages, we found that the mRNA and protein expression of IL-6 was robustly increased in a time-dependent and a dose-dependent manner. Our data demonstrated that PQ-induced IL-6 expression in macrophages plays a central role in pulmonary fibrosis through enhanced epithelial-to-mesenchymal transition (EMT). IL-6 expression and its role to enhance PQ-induced pulmonary fibrosis were increased by histone deacetylase (HDAC) inhibition and prevented by histone acetyltransferase (HAT) inhibition. In addition, the ability of CRISPR-ON transcription activation system (CRISPR-ON) to promote transcription of IL-6 was enhanced by HDAC inhibitor and blocked by HAT inhibitor. Chromatin immunoprecipitation experiments revealed that HDAC inhibitor increased histones activation marks H3K4me3 and H3K9ac at IL-6 promoter regions. In conclusion, IL-6 functioning through EMT in PQ-induced pulmonary fibrosis was regulated dynamically by HDAC and HAT both in vitro and in vivo via epigenetically regulating chromatin accessibility.