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Cell Aug 2020Checkpoint immunotherapy unleashes T cell control of tumors, but is undermined by immunosuppressive myeloid cells. TREM2 is a myeloid receptor that transmits...
Checkpoint immunotherapy unleashes T cell control of tumors, but is undermined by immunosuppressive myeloid cells. TREM2 is a myeloid receptor that transmits intracellular signals that sustain microglial responses during Alzheimer's disease. TREM2 is also expressed by tumor-infiltrating macrophages. Here, we found that Trem2 mice are more resistant to growth of various cancers than wild-type mice and are more responsive to anti-PD-1 immunotherapy. Furthermore, treatment with anti-TREM2 mAb curbed tumor growth and fostered regression when combined with anti-PD-1. scRNA-seq revealed that both TREM2 deletion and anti-TREM2 are associated with scant MRC1 and CXCR1 macrophages in the tumor infiltrate, paralleled by expansion of myeloid subsets expressing immunostimulatory molecules that promote improved T cell responses. TREM2 was expressed in tumor macrophages in over 200 human cancer cases and inversely correlated with prolonged survival for two types of cancer. Thus, TREM2 might be targeted to modify tumor myeloid infiltrates and augment checkpoint immunotherapy.
Topics: Animals; Antibodies, Monoclonal; CX3C Chemokine Receptor 1; Cell Line, Tumor; Disease Models, Animal; Humans; Immunotherapy; Lymphocytes, Tumor-Infiltrating; Membrane Glycoproteins; Methylcholanthrene; Mice; Mice, Inbred C57BL; Mice, Knockout; Neoplasms; Prognosis; Programmed Cell Death 1 Receptor; Receptors, Immunologic; Tumor Microenvironment
PubMed: 32783918
DOI: 10.1016/j.cell.2020.07.013 -
Acta Pharmaceutica Sinica. B Sep 2021Aberrant activation of NLRP3 inflammasome in colonic macrophages strongly associates with the occurrence and progression of ulcerative colitis. Although targeting NLRP3...
Aberrant activation of NLRP3 inflammasome in colonic macrophages strongly associates with the occurrence and progression of ulcerative colitis. Although targeting NLRP3 inflammasome has been considered to be a potential therapy, the underlying mechanism through which pathway the intestinal inflammation is modulated remains controversial. By focusing on the flavonoid lonicerin, one of the most abundant constituents existed in a long historical anti-inflammatory and anti-infectious herb Thunb., here we report its therapeutic effect on intestinal inflammation by binding directly to enhancer of zeste homolog 2 (EZH2) histone methyltransferase. EZH2-mediated modification of H3K27me3 promotes the expression of autophagy-related protein 5, which in turn leads to enhanced autophagy and accelerates autolysosome-mediated NLRP3 degradation. Mutations of EZH2 residues (His129 and Arg685) indicated by the dynamic simulation study have found to greatly diminish the protective effect of lonicerin. More importantly, studies verify that lonicerin dose-dependently disrupts the NLRP3-ASC-pro-caspase-1 complex assembly and alleviates colitis, which is compromised by administration of EZH2 overexpression plasmid. Thus, these findings together put forth the stage for further considering lonicerin as an anti-inflammatory epigenetic agent and suggesting EZH2/ATG5/NLRP3 axis may serve as a novel strategy to prevent ulcerative colitis as well as other inflammatory diseases.
PubMed: 34589402
DOI: 10.1016/j.apsb.2021.03.011 -
Autophagy Jun 2020Defective macroautophagy/autophagy and mitochondrial dysfunction are known to stimulate senescence. The mitochondrial regulator PPARGC1A (peroxisome proliferator...
UNLABELLED
Defective macroautophagy/autophagy and mitochondrial dysfunction are known to stimulate senescence. The mitochondrial regulator PPARGC1A (peroxisome proliferator activated receptor gamma, coactivator 1 alpha) regulates mitochondrial biogenesis, reducing senescence of vascular smooth muscle cells (VSMCs); however, it is unknown whether autophagy mediates PPARGC1A-protective effects on senescence. Using VSMCs, we identified the autophagy receptor SQSTM1/p62 (sequestosome 1) as a major regulator of autophagy and senescence of VSMCs. Abnormal autophagosomes were observed in VSMCs in aortas of mice. VSMCs in culture presented reductions in LC3-II levels; in autophagosome number; and in the expression of SQSTM1 (protein and mRNA), LAMP2 (lysosomal-associated membrane protein 2), CTSD (cathepsin D), and TFRC (transferrin receptor). Reduced SQSTM1 protein expression was also observed in aortas of mice and was upregulated by PPARGC1A overexpression, suggesting that SQSTM1 is a direct target of PPARGC1A. Inhibition of autophagy by 3-MA (3 methyladenine), spautin-1 or (autophagy related 5) siRNA stimulated senescence. Rapamycin rescued the effect of siRNA in , but not in VSMCs, suggesting that other targets of MTOR (mechanistic target of rapamycin kinase), in addition to autophagy, also contribute to senescence. siRNA increased senescence basally and in response to AGT II (angiotensin II) and zinc overload, two known inducers of senescence. Furthermore, gene deficiency mimicked the phenotype of depletion by presenting reduced autophagy and increased senescence and . Thus, PPARGC1A upregulates autophagy reducing senescence by a SQSTM1-dependent mechanism. We propose SQSTM1 as a novel target in therapeutic interventions reducing senescence.
ABBREVIATIONS
3-MA: 3 methyladenine; ACTA2/SM-actin: actin, alpha 2, smooth muscle, aorta; ACTB/β-actin: actin beta; AGT II: angiotensin II; ATG5: autophagy related 5; BECN1: beclin 1; CAT: catalase; CDKN1A: cyclin-dependent kinase inhibitor 1A (P21); Chl: chloroquine; CTSD: cathepsin D; CYCS: cytochrome C, somatic; DHE: dihydroethidium; DPBS: Dulbecco's phosphate-buffered saline; EL: elastic lamina; EM: extracellular matrix; FDG: fluorescein-di-β-D-galactopyranoside; GAPDH: glyceraldehyde-3-phosphate dehydrogenase; γH2AFX: phosphorylated H2A histone family, member X, HDCFDA: 2',7'-dichlorodihydrofluorescein diacetate; LAMP2: lysosomal-associated membrane protein 2; MASMs: mouse vascular smooth muscle cells; MEF: mouse embryonic fibroblast; NBR1: NBR1, autophagy cargo receptor; NFKB/NF-κB: nuclear factor of kappa light polypeptide gene enhancer in B cells; MTOR: mechanistic target of rapamycin kinase; NFE2L2: nuclear factor, erythroid derived 2, like 2; NOX1: NADPH oxidase 1; OPTN: optineurin; PFA: paraformaldehyde; PFU: plaque-forming units; PPARGC1A/PGC-1α: peroxisome proliferator activated receptor, gamma, coactivator 1 alpha; Ptdln3K: phosphatidylinositol 3-kinase; RASMs: rat vascular smooth muscle cells; ROS: reactive oxygen species; SA-GLB1/β-gal: senescence-associated galactosidase, beta 1; SASP: senescence-associated secretory phenotype; SIRT1: sirtuin 1; Spautin 1: specific and potent autophagy inhibitor 1; SQSTM1/p62: sequestosome 1; SOD: superoxide dismutase; TEM: transmission electron microscopy; TFEB: transcription factor EB; TFRC: transferrin receptor; TRP53/p53: transformation related protein 53; TUBG1: tubulin gamma 1; VSMCs: vascular smooth muscle cells; WT: wild type.
Topics: Animals; Aorta; Autophagosomes; Autophagy; Autophagy-Related Protein 5; Benzylamines; Brain; Cathepsin D; Cellular Senescence; Lysosomal-Associated Membrane Protein 2; Lysosomes; Male; Methylcholanthrene; Mice; Mice, Inbred C57BL; Mice, Knockout; Microscopy, Electron, Transmission; Myocytes, Smooth Muscle; Peroxisome Proliferator-Activated Receptor Gamma Coactivator 1-alpha; Quinazolines; RNA, Small Interfering; Rats; Rats, Sprague-Dawley; Reactive Oxygen Species; Receptors, Transferrin; Sequestosome-1 Protein; Sirolimus; Up-Regulation
PubMed: 31441382
DOI: 10.1080/15548627.2019.1659612 -
Archives of Pharmacal Research 2015Although various in vitro assays have been developed to evaluate the cytochrome P450 (CYP)-inducing potential of drug candidates, there is a continuing need for the...
Although various in vitro assays have been developed to evaluate the cytochrome P450 (CYP)-inducing potential of drug candidates, there is a continuing need for the development of a reliable model in drug discovery. The objective of the present study was to compare CYP induction by chemicals in HepG2 cells with Huh7, NKNT-3, and reverted NKNT-3 cells. HepG2 cells showed more similarity to human liver than the other cell lines in comparisons of the expression of cellular proteins. In evaluation of basal CYP activity, Huh7 cells exhibited the highest CYP1A2 and CYP3A4 activity, and HepG2 cells showed the highest CYP2B6 activity. The inducibility of CYP1A2, CYP2B6, and CYP3A4 by prototypical inducers was determined using enzyme assay, immunoblot analysis, and real-time PCR. Among the cells tested, HepG2 cells were highly responsive to CYP inducers, such as 3-methylcholanthrene for CYP1A2 and phenobarbital for CYP2B6 and CYP3A4. Moreover, HepG2 cells were responsive to various CYP1A2, CYP2B6, and CYP3A4 inducers as determined using fluorogenic and LC-MS/MS substrates. Thus, HepG2 cells may be comparable to human hepatocytes for the evaluation of CYP induction or slightly less sensitive. These results suggest HepG2 cells as a cell-based model in screening for CYP inducers in drug discovery.
Topics: Cell Line, Transformed; Cytochrome P-450 Enzyme Inducers; Drug Evaluation, Preclinical; Enzyme Induction; Hep G2 Cells; Hepatocytes; Humans; Xenobiotics
PubMed: 25336106
DOI: 10.1007/s12272-014-0502-6 -
Oncoimmunology 2018Immune checkpoint blockade (ICB) is currently evaluated in patients with glioblastoma (GBM), based on encouraging clinical data in other cancers, and results from...
Immune checkpoint blockade (ICB) is currently evaluated in patients with glioblastoma (GBM), based on encouraging clinical data in other cancers, and results from studies with the methylcholanthrene-induced GL261 mouse glioma. In this paper, we describe a novel model faithfully recapitulating some key human GBM characteristics, including low mutational load, a factor reported as a prognostic indicator of ICB response. Consistent with this observation, SB28 is completely resistant to ICB, contrasting with treatment sensitivity of the more highly mutated GL261. Moreover, SB28 shows features of a poorly immunogenic tumor, with low MHC-I expression and modest CD8 T-cell infiltration, suggesting that it may present similar challenges for immunotherapy as human GBM. Based on these key features for immune reactivity, SB28 may represent a treatment-resistant malignancy likely to mirror responses of many human tumors. We therefore propose that SB28 is a particularly suitable model for optimization of GBM immunotherapy.
PubMed: 30524896
DOI: 10.1080/2162402X.2018.1501137 -
Nature Cancer Feb 2021Complement has emerged as a component of tumor promoting inflammation. We conducted a systematic assessment of the role of complement activation and effector pathways in...
Complement has emerged as a component of tumor promoting inflammation. We conducted a systematic assessment of the role of complement activation and effector pathways in sarcomas. , and mice showed reduced susceptibility to 3-methylcholanthrene sarcomagenesis and transplanted sarcomas, whereas C1q and factor B deficiency had marginal effects. Complement 3a receptor (C3aR), but not C5aR1 and C5aR2, deficiency mirrored the phenotype of mice. C3 and C3aR deficiency were associated with reduced accumulation and functional skewing of tumor-associated macrophages, increased T cell activation and response to anti-PD-1 therapy. Transcriptional profiling of sarcoma infiltrating macrophages and monocytes revealed the enrichment of MHC II-dependent antigen presentation pathway in C3-deficient cells. In patients, C3aR expression correlated with a macrophage population signature and C3 deficiency-associated signatures predicted better clinical outcome. These results suggest that the lectin pathway and C3a/C3aR axis are key components of complement and macrophage-mediated sarcoma promotion and immunosuppression.
Topics: Animals; Complement Activation; Humans; Immunosuppression Therapy; Lectins; Mice; Monocytes; Receptor, Anaphylatoxin C5a; Receptors, Complement; Sarcoma
PubMed: 34505065
DOI: 10.1038/s43018-021-00173-0 -
Toxicology Aug 2023Aryl hydrocarbon receptor (AHR) is a ligand-dependent receptor that belongs to the superfamily of basic helix-loop-helix (bHLH) transcription factors. The activation of... (Review)
Review
Aryl hydrocarbon receptor (AHR) is a ligand-dependent receptor that belongs to the superfamily of basic helix-loop-helix (bHLH) transcription factors. The activation of the canonical AHR signaling pathway is known to induce the expression of cytochrome P450 enzymes, facilitating the detoxification metabolism in the human body. Additionally, AHR could interact with various signaling pathways such as epidermal growth factor receptor (EGFR), signal transducer and activator of transcription 3 (STAT3), hypoxia-inducible factor-1α (HIF-1α), nuclear factor ekappa B (NF-κβ), estrogen receptor (ER), and androgen receptor (AR) signaling pathways. Over the past 30 years, several studies have reported that various chemical, physical, or biological agents, such as tobacco, hydrocarbon compounds, industrial and agricultural chemical wastes, drugs, UV, viruses, and other toxins, could affect AHR expression or activity, promoting cancer development. Thus, it is valuable to overview how these factors regulate AHR-mediated carcinogenesis. Current findings have reported that many compounds could act as AHR ligands to drive the expressions of AHR-target genes, such as CYP1A1, CYP1B1, MMPs, and AXL, and other targets that exert a pro-proliferation or anti-apoptotic effect, like XIAP. Furthermore, some other physical and chemical agents, such as UV and 3-methylcholanthrene, could promote AHR signaling activities, increasing the signaling activities of a few oncogenic pathways, such as the phosphatidylinositol 3-kinase/protein kinase B (PI3K/AKT) and mitogen-activated protein kinase/extracellular signal-regulated kinase (MAPK/ERK) pathways. Understanding how various factors regulate AHR-mediated carcinogenesis processes helps clinicians and scientists plan personalized therapeutic strategies to improve anti-cancer treatment efficacy. As many studies that have reported the roles of AHR in regulating carcinogenesis are preclinical or observational clinical studies that did not explore the detailed mechanisms of how different chemical, physical, or biological agents promote AHR-mediated carcinogenesis processes, future studies should focus on conducting large-scale and functional studies to unravel the underlying mechanism of how AHR interacts with different factors in regulating carcinogenesis processes.
Topics: Humans; Receptors, Aryl Hydrocarbon; Phosphatidylinositol 3-Kinases; Basic Helix-Loop-Helix Transcription Factors; Extracellular Signal-Regulated MAP Kinases; Cytochrome P-450 CYP1A1; Biological Factors; Carcinogenesis
PubMed: 37480978
DOI: 10.1016/j.tox.2023.153596 -
Biological impact of environmental polycyclic aromatic hydrocarbons (ePAHs) as endocrine disruptors.Environmental Pollution (Barking, Essex... Jun 2016Polycyclic aromatic hydrocarbons (PAHs) are often detected in the environment and are regarded as endocrine disruptors. We here designated mixtures of PAHs in the... (Review)
Review
Polycyclic aromatic hydrocarbons (PAHs) are often detected in the environment and are regarded as endocrine disruptors. We here designated mixtures of PAHs in the environment as environmental PAHs (ePAHs) to discuss their effects collectively, which could be different from the sum of the constituent PAHs. We first summarized the biological impact of environmental PAHs (ePAHs) found in the atmosphere, sediments, soils, and water as a result of human activities, accidents, or natural phenomena. ePAHs are characterized by their sources and forms, followed by their biological effects and social impact, and bioassays that are used to investigate their biological effects. The findings of the bioassays have demonstrated that ePAHs have the ability to affect the endocrine systems of humans and animals. The pathways that mediate cell signaling for the endocrine disruptions induced by ePAHs and PAHs have also been summarized in order to obtain a clearer understanding of the mechanisms responsible for these effects without animal tests; they include specific signaling pathways (MAPK and other signaling pathways), regulatory mechanisms (chromatin/epigenetic regulation, cell cycle/DNA damage control, and cytoskeletal/adhesion regulation), and cell functions (apoptosis, autophagy, immune responses/inflammation, neurological responses, and development/differentiation) induced by specific PAHs, such as benz[a]anthracene, benzo[a]pyrene, benz[l]aceanthrylene, cyclopenta[c,d]pyrene, 7,12-dimethylbenz[a]anthracene, fluoranthene, fluorene, 3-methylcholanthrene, perylene, phenanthrene, and pyrene as well as their derivatives. Estrogen signaling is one of the most studied pathways associated with the endocrine-disrupting activities of PAHs, and involves estrogen receptors and aryl hydrocarbon receptors. However, some of the actions of PAHs are contradictory, complex, and unexplainable. Although several possibilities have been suggested, such as direct interactions between PAHs and receptors and the suppression of their activities through other pathways, the mechanisms underlying the activities of PAHs remain unclear. Thus, standardized assay protocols for pathway-based assessments are considered to be important to overcome these issues.
Topics: Animals; Biological Assay; DNA Damage; Endocrine Disruptors; Environmental Exposure; Environmental Pollutants; Epigenesis, Genetic; Humans; Polycyclic Aromatic Hydrocarbons; Receptors, Aryl Hydrocarbon
PubMed: 27038213
DOI: 10.1016/j.envpol.2016.03.050 -
Ecotoxicology and Environmental Safety Oct 2018Many chemicals produced by human activities end up in the aquatic ecosystem causing adverse developmental and reproductive effects in aquatic organisms. There is...
Many chemicals produced by human activities end up in the aquatic ecosystem causing adverse developmental and reproductive effects in aquatic organisms. There is evidence that some anthropogenic chemicals disturb bone formation and skeletal development but the lack of suitable in vitro and in vivo systems for testing has hindered the identification of underlying mechanisms of osteotoxicity. Several fish systems - an in vitro cell system to study extracellular matrix mineralization and in vivo systems to evaluate bone formation and skeletogenesis - were combined to collect data on the osteotoxic activity of 3-methylcholanthrene (3-MC), a polycyclic aromatic hydrocarbon. Anti-mineralogenic effects, increased incidence of skeletal deformities and reduced bone formation and regeneration were observed in zebrafish upon exposure to 3-MC. Pathway reporter array revealed the role of the aryl hydrocarbon receptor 2 (Ahr2) in the mechanisms underlying 3-MC osteotoxicity in mineralogenic cell lines. Analysis of gene expression in zebrafish larvae confirmed the role of Ahr2 in the signaling of 3-MC toxicity. It also indicated a possible complementary action of the pregnane X receptor (Pxr) in the regulation of genes involved in bone cell activity and differentiation but also in xenobiotic metabolism. Data reported here demonstrated the osteotoxicity of 3-MC but also confirmed the suitability of fish systems to gain insights into the toxic mechanisms of compounds affecting skeletal and bone formation.
Topics: Animals; Calcification, Physiologic; Cell Line; Humans; Larva; Methylcholanthrene; Osteogenesis; Receptors, Aryl Hydrocarbon; Signal Transduction; Zebrafish
PubMed: 29940513
DOI: 10.1016/j.ecoenv.2018.06.035 -
Methods in Cell Biology 2021Mouse models of cancer are essential in furthering our understanding both of the mechanisms that drive tumor development and the immune response that develops in...
Mouse models of cancer are essential in furthering our understanding both of the mechanisms that drive tumor development and the immune response that develops in parallel, and also in providing a platform for testing novel anti-cancer therapies. The majority of solid tumor models available rely on the injection of existing cancer cell lines into naïve hosts which, while providing quick and reproducible model systems, typically lack the development of a tumor microenvironment that recapitulates those seen in human cancers. Administration of the carcinogen 3-methylcholanthrene (MCA), allows tumors to develop in situ, forming a tumor microenvironment with an established stroma and vasculature. This article provides a detailed set of protocols for the administration of MCA into mice and the subsequent monitoring of tumors. Protocols are also provided for some of the routinely used downstream applications that can be used for MCA tumors.
Topics: Animals; Disease Models, Animal; Fibrosarcoma; Immunity; Methylcholanthrene; Mice; Tumor Microenvironment
PubMed: 33785169
DOI: 10.1016/bs.mcb.2020.09.007