ABSTRACT
OBJECTIVES: During the manufacturing of Porcelain Veneered Zirconia (PVZ) dental crowns, the veneer-core system undergoes high-temperature firing cycles and gets fused together which is then, under a controlled setting, cooled down to room temperature. During this cooling process, the mismatch in thermal properties between zirconia and porcelain leads to the development of transient and residual thermal stresses within the crown. These thermal stresses are inherent to the PVZ dental crown systems and render the crown structure weak, acting as a precursor to veneer chipping, fracture, and delamination. In this study, the introduction of an intermediate functionally graded material (FGM) layer at the bi-material interface is investigated as a potentially viable alternative for providing a smoother transition of properties between zirconia and porcelain in a PVZ crown system. METHODS: Anatomically correct 3D crown models were developed for this study, with and without the FGM layer modeled at the bi-material interface. A viscoelastic finite element model was developed and validated for an anatomically correct bilayer PVZ crown system which was then used for predicting residual and transient stresses in the bilayer PVZ crown. Subsequently, the viscoelastic finite element model was further extended for the analysis of graded sublayers within the FGM layer, and this extended model was used for predicting the residual and transient stresses in the functionally graded PVZ crown, with an FGM layer at the bi-material interface. RESULTS: The study showed that the introduction of an FGM layer at the bi-material interface has the potential to reduce the effects from transient and residual stresses within the PVZ crown system relative to a bilayer PVZ crown structure. Furthermore, the study revealed that the FGM layer causes stress redistribution to alleviate the stress concentration at the interfacial surface between porcelain and zirconia which can potentially enhance the durability of the PVZ crowns towards interfacial debonding or fracture. SIGNIFICANCE: Thus, the use of an FGM layer at the bi-material interface shows a good prospect for enhancing the longevity of the PVZ dental crown restorations by alleviating the abrupt thermal property difference and relaxing thermal stresses.
Subject(s)
Crowns , Dental Porcelain , Dental Veneers , Finite Element Analysis , Zirconium , Zirconium/chemistry , Dental Porcelain/chemistry , Materials Testing , Viscosity , Elasticity , Surface Properties , Dental Stress Analysis , Dental Prosthesis Design , Dental Materials/chemistryABSTRACT
There is evidence that the orphan nuclear receptor 4A1 (NR4A1, Nur77) is overexpressed in exhausted CD8 + T cells and regulates PD-L1 in tumors. This study investigated the effects of potent bis-indole-derived NR4A1 antagonists on reversing T-cell exhaustion and downregulating PD-L1 in colon tumors/cells. NR4A1 antagonists inhibited colon tumor growth and downregulated expression of PD-L1 in mouse colon MC-38-derived tumors and cells. TILs from MC-38 cell-derived colon tumors and splenic lymphocytes exhibited high levels of the T-cell exhaustion markers including PD-1, 2B4, TIM3+ and TIGIT and similar results were observed in the spleen, and these were inhibited by NR4A1 antagonists. In addition, treatment with NR4A1 antagonists induced cytokine activation markers interferon γ, granzyme B and perforin mRNAs and decreased TOX, TOX2 and NFAT in TIL-derived CD8 + T cells. Thus, NR4A1 antagonists decrease NR4A1-dependent pro-oncogenic activity and PD-L1 expression in colon tumors and inhibit NR4A1-dependent T-cell exhaustion in TILs and spleen and represent a novel class of mechanism-based drugs that enhance immune surveillance in tumors.
Subject(s)
B7-H1 Antigen , Colonic Neoplasms , Animals , Mice , T-Cell Exhaustion , Spleen , Colonic Neoplasms/drug therapy , CD8-Positive T-Lymphocytes , Indoles/pharmacologyABSTRACT
Paraspeckles compound 1 (PSPC1) is a multifunctional protein that plays an important role in cancer cells, where PSPC1 is a master regulator of pro-oncogenic responses that includes activation of TGFß (TGFß1), TGFß-dependent EMT, and metastasis. The pro-oncogenic activities of PSPC1 closely resembled those observed for the orphan nuclear receptor 4A1 (NR4A1, Nur77) and knockdown of NR4A1 decreased expression of PSPC1 in MDA-MB-231 breast, H1299 lung, and SNU449 liver cancer cells. Similar results were observed in these same cell lines after treatment with bisindole-derived (CDIMs) NR4A1 antagonists. Moreover, PSPC1-dependent regulation of TGFß, genes associated with cancer stem cells and epithelial to mesenchymal transition (EMT) were also downregulated after NR4A1 silencing or treatment of breast, lung, and liver cancer cells with CDIM/NR4A1 antagonists. Results of chromatin immunoprecipitation (ChIP) assays suggest that NR4A1 regulates PSPC1 through interaction with an NBRE sequence in the PSPC1 gene promoter. These results coupled with in vivo studies showing that NR4A1 antagonists inhibit breast tumor growth and downregulate PSPC1 in tumors indicate that the pro-oncogenic nuclear PSPC1 factor can be targeted by CDIM/NR4A1 antagonists.
Subject(s)
Breast Neoplasms/drug therapy , Methane/administration & dosage , Nuclear Receptor Subfamily 4, Group A, Member 1/metabolism , Promoter Regions, Genetic , RNA-Binding Proteins/genetics , A549 Cells , Animals , Breast Neoplasms/genetics , Breast Neoplasms/metabolism , Breast Neoplasms/pathology , Cell Line, Tumor , Cell Proliferation/drug effects , Cell Survival/drug effects , Epithelial-Mesenchymal Transition/drug effects , Female , HCT116 Cells , Hep G2 Cells , Humans , Methane/pharmacology , Mice , Neoplasm Transplantation , Neoplastic Stem Cells/drug effects , Neoplastic Stem Cells/metabolism , Nuclear Receptor Subfamily 4, Group A, Member 1/antagonists & inhibitors , PC-3 Cells , Promoter Regions, Genetic/drug effects , RNA-Binding Proteins/metabolism , Transforming Growth Factor beta1/metabolism , Xenograft Model Antitumor AssaysABSTRACT
BACKGROUND: Flavonoids exhibit both chemopreventive and chemotherapeutic activity for multiple tumor types, however, their mechanisms of action are not well defined. Based on some of their functional and gene modifying activities as anticancer agents, we hypothesized that kaempferol and quercetin were nuclear receptor 4A1 (NR4A1, Nur77) ligands and confirmed that both compounds directly bound NR4A1 with KD values of 3.1 and 0.93 µM, respectively. METHODS: The activities of kaempferol and quercetin were determined in direct binding to NR4A1 protein and in NR4A1-dependent transactivation assays in Rh30 and Rh41 rhabdomyosarcoma (RMS) cells. Flavonoid-dependent effects as inhibitors of cell growth, survival and invasion were determined in XTT and Boyden chamber assays respectively and changes in protein levels were determined by western blots. Tumor growth inhibition studies were carried out in athymic nude mice bearing Rh30 cells as xenografts. RESULTS: Kaempferol and quercetin bind NR4A1 protein and inhibit NR4A1-dependent transactivation in RMS cells. NR4A1 also regulates RMS cell growth, survival, mTOR signaling and invasion. The pro-oncogenic PAX3-FOXO1 and G9a genes are also regulated by NR4A1 and, these pathways and genes are all inhibited by kaempferol and quercetin. Moreover, at a dose of 50 mg/kg/d kaempferol and quercetin inhibited tumor growth in an athymic nude mouse xenograft model bearing Rh30 cells. CONCLUSION: These results demonstrate the clinical potential for repurposing kaempferol and quercetin for clinical applications as precision medicine for treating RMS patients that express NR4A1 in order to increase the efficacy and decrease dosages of currently used cytotoxic drugs.
Subject(s)
Flavonoids/metabolism , Kaempferols/metabolism , Quercetin/metabolism , Receptors, Cytoplasmic and Nuclear/metabolism , Rhabdomyosarcoma/genetics , Animals , Female , Humans , Ligands , Mice , Mice, Nude , Rhabdomyosarcoma/pathologyABSTRACT
Specificity protein (Sp) transcription factors (TFs) Sp1, Sp3 and Sp4, and the orphan nuclear receptor 4A1 (NR4A1) are highly expressed in pancreatic tumors and Sp1 is a negative prognostic factor for pancreatic cancer patient survival. Results of knockdown and overexpression of Sp1, Sp3 and Sp4 in pancreatic and other cancer lines show that these TFs are individually pro-oncogenic factors and loss of one Sp TF is not compensated by other members. NR4A1 is also a pro-oncogenic factor and both NR4A1 and Sp TFs exhibit similar functions in pancreatic cancer cells and regulate cell growth, survival, migration and invasion. There is also evidence that Sp TFs and NR4A1 regulate some of the same genes including survivin, epidermal growth factor receptor, PAX3-FOXO1, α5- and α6-integrins, ß1-, ß3- and ß4-integrins; this is due to NR4A1 acting as a cofactor and mediating NR4A1/Sp1/4-regulated gene expression through GC-rich gene promoter sites. Several studies show that drugs targeting Sp downregulation or NR4A1 antagonists are highly effective inhibitors of Sp/NR4A1-regulated pathways and genes in pancreatic and other cancer cells, and the triterpenoid celastrol is a novel dual-acting agent that targets both Sp TFs and NR4A1.
Subject(s)
Pancreatic Neoplasms , Transcription Factors , Cell Line, Tumor , Gene Expression Regulation, Neoplastic , Humans , Oncogenes , Pancreatic Neoplasms/drug therapy , Pancreatic Neoplasms/genetics , Receptors, Cytoplasmic and Nuclear/genetics , Sp Transcription Factors/genetics , Sp Transcription Factors/metabolism , Transcription Factors/geneticsABSTRACT
Background and objective The prevalence of non-alcoholic fatty liver disease (NAFLD) is 60% in patients with type 2 diabetes mellitus (T2DM). NAFLD can lead to non-alcoholic steatohepatitis (NASH), both of which are the leading causes of cirrhosis. This study was undertaken to evaluate whether empagliflozin, a sodium-glucose cotransporter-2 (SGLT-2) inhibitor, reduces liver fat content in these patients after therapy. Methods After enrolling patients of T2DM with NAFLD, they were administered empagliflozin 10 mg once daily orally for six months without modifying existing oral hypoglycemic agents (OHA) if any. All demographic data were collected, and anthropometric measurements, as well as laboratory investigations, were performed, and controlled attenuation parameter (CAP) and liver stiffness (LS) were measured using FibroScan® (Echosens, Paris, France) at baseline, and six months of therapy. The adverse effects related to therapy were also taken into account. Results There was a significant decrease in mean CAP value from 282.07 ± 47.29 dB/m to 263.07 ± 49.93 dB/m and LS from 5.89 ± 4.23 kPa to 5.04 ± 1.49 kPa along with a significant decrease in serum alanine aminotransferase (ALT), aspartate aminotransferase (AST), and gamma-glutamyl transferase (GGT) among the patients. Compared to the baseline, there was a significant reduction in post-treatment weight, body mass index (BMI), and blood pressure (BP). The most commonly observed adverse effects of the therapy were urinary tract infection (UTI) (17.8%), nasopharyngitis (11.9%), and hypoglycemia (10.71%). Conclusion A reduction in hepatic fat content was seen in our prospective study cohort after six months of empagliflozin therapy. Empagliflozin also led to beneficial effects such as weight loss and reduction in transaminases and GGT. Given the absence of significant side effects of the therapy, empagliflozin could be used as an effective treatment modality for T2DM patients with NAFLD, which are two conditions commonly seen in combination.
ABSTRACT
Background Assessment of nonalcoholic fatty liver disease (NAFLD) includes estimation of liver fat (steatosis). Controlled attenuation parameter (CAP) value obtained by FibroScan® (Echosens, Paris, France) is an alternative to liver biopsy for diagnosing and estimating steatosis (S). This study aimed to estimate the liver fat by CAP in NAFLD patients. Methods An observational cross-sectional study was conducted at the Liver Unit of Bir Hospital, from January 2021 to May 2021 after ethical clearance from the Institutional Review Board of the National Academy of Medical Sciences. A convenient sampling method was used. Data were analyzed with descriptive and inferential statistics involving bivariate and multivariate analysis. Results A total of 127 NAFLD patients were enrolled. The mean (±SD) CAP value was 271.53 (±50.69) dB/m. Total cholesterol, triglyceride, and body mass index (BMI) correlated positively (p<0.05) while systolic blood pressure correlated negatively with CAP value (p=0.031). On multivariate analysis, patients with BMI ≥25 kg/m2 were found 3.7 times more likely to have CAP ≥291 dB/m (S3, severe steatosis) than those with BMI <25 kg/m2 (p=0.048, 95% CI 1.01, 13.50). The mean (±SD) CAP values were 276.19 (±49.93) and 246.60 (±48.50) dB/m among those with BMI ≥25 kg/m2 and <25 kg/m2, respectively (p=0.016, using independent t-test). CAP steatosis grading correlated positively with both the ultrasound grading (p<0.001) and fibrosis grading by liver stiffness measurement (p=0.004). Conclusion In this observational cross-sectional study of NAFLD patients, the mean (±SD) CAP value was 271.53 (±50.69) dB/m, which corresponds to moderate steatosis (S2). Obese NAFLD patients with ≥25 kg/m2 were 3.7 times more likely to have severe steatosis (S3) than nonobese NAFLD patients with BMI <25 kg/m2.
ABSTRACT
Access to daily high-resolution gridded surface weather data based on direct observations and over long time periods is essential for many studies and applications including vegetation, wildlife, soil health, hydrological modelling, and as driver data in Earth system models. We present Daymet V4, a 40-year daily meteorological dataset on a 1 km grid for North America, Hawaii, and Puerto Rico, providing temperature, precipitation, shortwave radiation, vapor pressure, snow water equivalent, and day length. The dataset includes an objective quantification of uncertainty based on strict cross-validation analysis for temperature and precipitation results. The dataset represents several improvements from a previous version, and this data descriptor provides complete documentation for updated methods. Improvements include: reductions in the timing bias of input reporting weather station measurements; improvement to the three-dimensional regression model techniques in the core algorithm; and a novel approach to handling high elevation temperature measurement biases. We show cross-validation analyses with the underlying weather station data to demonstrate the technical validity of new dataset generation methods, and to quantify improved accuracy.
ABSTRACT
Nuclear receptor 4A1 (NR4A1, Nur77, TR3) is more highly expressed in breast and solid tumors compared to non-tumor tissues and is a pro-oncogenic factor in solid tumor-derived cancers. NR4A1 regulates cancer cell growth, survival, migration, and invasion, and bis-indole-derived compounds (CDIMs) that bind NR4A1 act as antagonists and inhibit tumor growth. Preliminary structure-binding studies identified 1,1-bis(3'-indolyl)-1-(3,5-disubstitutedphenyl)methane analogs as NR4A1 ligands with low KD values; we further investigated the anticancer activity of the four most active analogs (KD's ≤ 3.1 µM) in breast cancer cells and in athymic mouse xenograft models. The treatment of MDA-MB-231 and SKBR3 breast cancer cells with the 3-bromo-5-methoxy, 3-chloro-5-trifluoromethoxy, 3-chloro-5-trifluoromethyl, and 3-bromo-5-trifluoromethoxy phenyl-substituted analogs decreased cell growth and the expression of epidermal of growth factor receptor (EGFR), hepatocyte growth factor receptor (cMET), and PD-L1 as well as inhibited mTOR phosphorylation. In addition, all four compounds inhibited tumor growth in athymic nude mice bearing MDA-MB-231 cells (orthotopic) at a dose of 1 mg/kg/d, which was not accompanied by changes in body weight. These 3,5-disubstituted analogs were the most potent CDIM/NR4A1 ligands reported and are being further developed for clinical applications.
ABSTRACT
The nuclear receptor (NR) superfamily of transcription factors encodes expression of 48 human genes that are important for maintaining cellular homeostasis and in pathophysiology, and this has been observed for all sub-families including orphan receptors for which endogenous ligands have not yet been identified. The orphan NR4A1 (Nur77 and TR3) and other members of this sub-family (NR4A2 and NR4A3) are immediate early genes induced by diverse stressors, and these receptors play an important role in the immune function and are up-regulated in some inflammatory diseases including solid tumors. Although endogenous ligands for NR4A have not been identified, several different classes of compounds have been characterized as NR4A1 ligands that bind the receptor. These compounds include cytosporone B and structurally related analogs, bis-indole derived (CDIM) compounds, the triterpenoid celastrol and a number of other chemicals including polyunsaturated fatty acids. NR4A1 ligands bind different regions/surfaces of NR4A1 and exhibit selective NR4A1 modulator (SNR4AM) activities that are dependent on ligand structure and cell/tissue context. NR4A1 ligands exhibit pharmacologic activities in studies on cancer, endometriosis metabolic and inflammatory diseases and are promising agents with clinical potential for treating multiple diseases.
Subject(s)
Neoplasms , Orphan Nuclear Receptors , Female , Gene Expression Regulation , Humans , Ligands , Neoplasms/genetics , Nuclear Receptor Subfamily 4, Group A, Member 1/genetics , Nuclear Receptor Subfamily 4, Group A, Member 1/metabolism , Orphan Nuclear Receptors/genetics , Orphan Nuclear Receptors/metabolism , Orphan Nuclear Receptors/therapeutic use , Signal TransductionABSTRACT
Flavonoids are polyphenolic phytochemicals produced in fruits, nuts and vegetables and dietary consumption of these structurally diverse compounds is associated with multiple health benefits including increased lifespan, decreased cardiovascular problems and low rates of metabolic diseases. Preclinical studies with individual flavonoids demonstrate that these compounds exhibit anti-inflammatory and anticancer activities and they enhance the immune system. Their effectiveness in both chemoprevention and chemotherapy is associated with their targeting of multiple genes/pathways including nuclear receptors, the aryl hydrocarbon receptor (AhR), kinases, receptor tyrosine kinases and G protein-coupled receptors. However, despite the remarkable preclinical activities of flavonoids, their clinical applications have been limited and this is due, in part, to problems in drug delivery and poor bioavailability and these problems are being addressed. Further improvements that will expand clinical applications of flavonoids include mechanism-based precision medicine approaches which will identify critical mechanisms of action of individual flavonoids with optimal activities that can be used in combination therapies.
ABSTRACT
Pancreatic ductal adenocarcinoma (PDAC) is a highly aggressive cancer with poor prognosis and chemotherapy with gemcitabine has limited effects and is associated with development of drug resistance. Treatment of Panc1 and MiaPaca2 pancreatic cancer cells with gemcitabine induced expression of the orphan nuclear receptor 4A2 (NURR1) and analysis of the cancer genome atlas indicated the NURR1 is overexpressed in pancreatic tumors and is a negative prognostic factor for patient survival. Results of NURR1 knockdown or treatment with the NURR1 antagonist 1,1-bis(3Î-indolyl)-1-(p-chlorophenyl)methane (C-DIM 12) demonstrated that NURR1 was pro-oncogenic in pancreatic cancer cells and regulated cancer cell and tumor growth and survival. NURR1 is induced by gemcitabine and serves as a key drug-resistance factor and is also required for gemcitabine-induced cytoprotective autophagy. NURR1 regulated genes were determined by RNA sequencing of mRNAs expressed in MiaPaCa2 cells expressing NURR1 and in CRISPR/Cas9 gene edited cells for NURR1 knockdown and KEGG enrichment analysis of the differentially expressed genes showed that autophagy was the major pathway regulated by NURR1. Moreover, NURR1 regulated expression of two major autophagic genes ATG7 and ATG12 which are also overexpressed in pancreatic tumors and like NURR1 are negative prognostic factors for patient survival. Thus, gemcitabine-induced cytoprotective autophagy is due to the NURR1 - ATG7/ATG12 axis and this can be targeted and disrupted by NURR1 antagonist C-DIM12 demonstrating the potential clinical applications for combination therapies with gemcitabine and NURR1 antagonists.
Subject(s)
Carcinoma, Pancreatic Ductal , Pancreatic Neoplasms , Humans , Drug Resistance, Neoplasm/genetics , Pancreatic Neoplasms/drug therapy , Gemcitabine , Carcinoma, Pancreatic Ductal/drug therapy , Receptors, Cytoplasmic and Nuclear , Autophagy/genetics , Nuclear Receptor Subfamily 4, Group A, Member 2/genetics , Pancreatic NeoplasmsABSTRACT
The histone methyltransferase G9A (EHMT2) gene catalyzes methylation of histone 3 lysine 9 (H3K9), and this gene silencing activity contributes to the tumor promoter-like activity of G9A in several tumor types including alveolar rhabdomyosarcoma (ARMS). Previous studies show the orphan nuclear receptor 4A1 (NR4A1, Nur77) is overexpressed in rhabdomyosarcoma and exhibits pro-oncogenic activity. In this study, we show that knockdown of NR4A1 in ARMS cells decreased expression of G9A mRNA and protein. Moreover, treatment of ARMS cells with several bis-indole-derived NR4A1 ligands (antagonists) including 1,1-bis(3'-indolyl)-1-(4-hydroxyphenyl)methane (CDIM8), 3,5-dimethyl (3,5-(CH3)2), and 3-bromo-5-methoxy (3-Br-5-OCH3) analogs also decreased G9A expression. Furthermore, NR4A1 antagonists also decreased G9A expression in breast, lung, liver, and endometrial cancer cells confirming that G9A is an NR4A1-regulated gene in ARMS and other cancer cell lines. Mechanistic studies showed that the NR4A1/Sp1 complex interacted with the GC-rich 511 region of the G9A promoter to regulate G9A gene expression. Moreover, knockdown of NR4A1 or treatment with NR4A1 receptor antagonists decreased overall H3K9me2, H3K9me2 associated with the PTEN promoter, and PTEN-regulated phospho-Akt. In vivo studies showed that the NR4A1 antagonist (3-Br-5-OCH3) inhibited tumor growth in athymic nude mice bearing Rh30 ARMS cells and confirmed that G9A was an NR4A1-regulated gene that can be targeted by NR4A1 receptor antagonists.
Subject(s)
Histone Methyltransferases/metabolism , Nuclear Receptor Subfamily 4, Group A, Member 1/metabolism , Rhabdomyosarcoma, Alveolar/genetics , Animals , Female , Humans , Mice , Mice, NudeABSTRACT
Transforming growth factor ß (TGFß) enhances invasion of breast and lung cancer cells through phosphorylation-dependent nuclear export of the nuclear receptor 4A1 (NR4A1, Nur77). This response is inhibited by the NR4A1 antagonist 1,1-bis(3'-indoly)-1-(p-hydroxyphenyl) methane (CDIM8) and we hypothesized that similar effects would be observed in Rhabdomyosarcoma (RMS) cells. Although some kinase inhibitors block TGFß-induced invasion of embryonal RMS (ERMS) cells, the mechanism differs from breast and lung cancer cells since NR4A1 is extranuclear in ERMS cells. However, CDIM8 blocks basal and TGFß-induced invasion of RD and SMS-CTR ERMS cell lines but not Rh30 alveolar RMS (ARMS) cells. Moreover, this response in ERMS cells was independent of SMAD7 degradation or activation of SMAD2/SMAD3. ß-Catenin silencing decreased ERMS cell invasion and CDIM8 induced proteasome-independent downregulation of ß-catenin. The novel mechanism of CDIM8-mediated inhibition of basal and TGFß-induced ERMS cell invasion was due to activation of the Bcl-2-NR4A1 complex, mitochondrial disruption, induction of the tumor suppressor-like cytokine interleukin-24 (IL-24) which in turn downregulates ß-catenin expression. Thus, the NR4A1 antagonist inhibits TGFß-induced invasion of ERMS cells through initial targeting of cytosolic NR4A1.
ABSTRACT
Coronavirus disease 2019, the new public health emergency that originated in China, is spreading rapidly across the globe with limited tools to confine this growing pandemic. The virus, severe acute respiratory syndrome coronavirus 2, is transmitted by droplet infection from person to person. Our current understanding of the disease spectrum is limited. The proportion of infected children is significantly less compared to adults with the majority of them showing mild symptoms. More than half of symptomatic children present with fever and cough. However, the extent of asymptomatic infection in children and the role they play in community transmission is still undetermined. Although there are case reports of neonates infected with severe acute respiratory syndrome coronavirus 2, vertical transmission from infected mother to new-born is yet to be proven. The disease is confirmed by demonstration of the virus by real-time reverse transcriptase-polymerase chain reaction in respiratory secretions. Due to the lack of specific antiviral agents, we rely on infection-control measures to prevent disease spread and on supportive care for infected ones. This article has summarized the clinical characteristics of children with coronavirus disease 2019 based on published case reports.
Subject(s)
Asymptomatic Infections/epidemiology , Coronavirus Infections/epidemiology , Coronavirus Infections/physiopathology , Pneumonia, Viral/epidemiology , Pneumonia, Viral/physiopathology , Adolescent , Betacoronavirus , COVID-19 , Child , Child, Preschool , Coronavirus Infections/therapy , Coronavirus Infections/transmission , Humans , Infant , Infant, Newborn , Infection Control , Infectious Disease Transmission, Vertical , Pandemics , Pneumonia, Viral/therapy , Pneumonia, Viral/transmission , SARS-CoV-2 , Severity of Illness IndexABSTRACT
Background: The aryl hydrocarbon receptor (AhR) is expressed in gliomas and the highest staining is observed in glioblastomas. A recent study showed that the AhR exhibited tumor suppressor-like activity in established and patient-derived glioblastoma cells and genomic analysis showed that this was due, in part, to suppression of CXCL12, CXCR4 and MMP9. Methods: Selective AhR modulators (SAhRMs) including AhR-active pharmaceuticals were screened for their inhibition of invasion using a spheroid invasion assay in patient-derived AhR-expressing 15-037 glioblastoma cells and in AhR-silenced 15-037 cells. Invasion, migration and cell proliferation were determined using spheroid invasion, Boyden chambers and scratch assay, and XTT metabolic assays for cell growth. Changes in gene and gene product expression were determined by real-time PCR and Western blot assays, respectively. In vivo antitumorigenic activity of omeprazole was determined in SCID mice bearing subcutaneous patient-derived 15-037 cells. Results: Results of a screening assay using patient-derived 15-037 cells (wild-type and AhR knockout) identified the AhR-active proton pump inhibitor omeprazole as an inhibitor of glioblastoma cell invasion and migration only AhR-expressing cells but not in cells where the AhR was downregulated. Omeprazole also enhanced AhR-dependent repression of the pro-invasion CXCL12, CXCR4 and MMP9 genes, and interactions and effectiveness of omeprazole plus temozolomide were response-dependent. Omeprazole (100 mg/kg/injection) inhibited and delayed tumors in SCID mice bearing patient-derived 15-037 cells injected subcutaneously. Conclusion: Our results demonstrate that omeprazole enhances AhR-dependent inhibition of glioblastoma invasion and highlights a potential new avenue for development of a novel therapeutic mechanism-based approach for treating glioblastoma.
ABSTRACT
Bis-indole derivatives including 1,1-bis(3'-indolyl)-1-(4-chlorophenyl)methane (DIM-C-pPhCl) and substituted quinolines such as chloroquine (CQ) and amodiaquine (AQ) are nuclear receptor 4A2 (NR4A2, Nurr1) ligands, and they exhibit anti-inflammatory activities in mouse and rat models of Parkinson's disease, respectively. However, computational modeling demonstrates that the quinoline derivatives interact with the ligand-binding domain, whereas the bis-indoles preferentially interact with a C-terminal cofactor binding site of NR4A2. In this study, the effects of DIM-C-pPhCl and related analogs were compared with CQ/AQ as inducers of NR4A2-responsive genes including vasoactive intestinal peptide, osteopontin, proopiomelanocortin, and neuropilin 1 in Panc1 and Panc28 pancreatic cancer cells. The results demonstrate that, among the bis-indole analogs, their relative potencies as inducers were structure-gene- and cell context dependent. In contrast, CQ and AQ were significantly less potent than the bis-indole derivatives and, for some of the NR4A2-regulated genes, CQ and AQ were inactive as inducers. These results demonstrate that although bis-indole and quinoline derivatives have been characterized as activators of NR4A2-dependent gene expression, these two classes of compounds exhibit different activities, indicating that they are selective NR4A2 modulators.
Subject(s)
Gene Expression Regulation, Neoplastic/drug effects , Indoles , Neoplasm Proteins/metabolism , Nuclear Receptor Subfamily 4, Group A, Member 2/agonists , Pancreatic Neoplasms/metabolism , Quinolines , Animals , Cell Line, Tumor , Humans , Indoles/chemical synthesis , Indoles/chemistry , Indoles/pharmacology , Mice , Nuclear Receptor Subfamily 4, Group A, Member 2/metabolism , Pancreatic Neoplasms/pathology , Quinolines/chemical synthesis , Quinolines/chemistry , Quinolines/pharmacology , Rats , Structure-Activity RelationshipABSTRACT
Leptospirosis is an important zoonotic disease in Nepal; however, there is a lack of information on sources of leptospirosis infection for people and associated risk factors. We implemented a case-control study nested within a cross-sectional survey to investigate zoonotic risks of human leptospirosis among adult, febrile patients seeking treatment in healthcare centres in Kaski District, Nepal, from April to October 2013. The study population was 239 febrile patients; the data consisted of paired blood samples; questionnaires on clinical symptoms; occupational, environmental and animal exposures; and a blood sample from animals in the household. In total, 63 cattle, 92 buffalo, 181 goats, 20 dogs and 14 rodents from 119 households were blood sampled. Serology was performed on the samples using the microscopic agglutination test (MAT) for a panel of 20 serovars with a starting dilution of 1:50. Clinical leptospirosis was defined as a titre of 1:400 or stronger, or a 4-fold or greater rise between acute and convalescent titres, or evidence of seroconversion for one or more serovars represented by a titre of <1:50 in the acute sample and a titre of ≥1:100 in the convalescent sample. The prevalence of clinical leptospirosis was 5.4% (95% CI 2.6%-8.3%). The most common symptoms among recruited participants were loss of appetite and lethargy followed by chills, profuse sweating and backache. No individual clinical symptom nor combination of any two symptoms was significantly associated with clinical leptospirosis. However, owning goats (OR 1.3, CI 95% 1.05-1.66), working in rice fields (OR 1.3, CI 95% 1.11-1.72) and male gender (OR 4, CI 95% 1.12-17.26) significantly increased the risk of clinical leptospirosis in humans. Findings suggest that leptospirosis should be considered in the clinical differential diagnosis among febrile adult patients in Nepal, especially for men, goat owners and/or those who work in rice fields.
Subject(s)
Leptospira/isolation & purification , Leptospirosis/epidemiology , Zoonoses/epidemiology , Zoonoses/transmission , Adolescent , Adult , Animals , Case-Control Studies , Cattle , Cattle Diseases/blood , Cattle Diseases/epidemiology , Cattle Diseases/microbiology , Cross-Sectional Studies , Diagnosis, Differential , Dog Diseases/blood , Dog Diseases/epidemiology , Dog Diseases/microbiology , Dogs , Female , Fever/epidemiology , Fever/microbiology , Goat Diseases/blood , Goat Diseases/epidemiology , Goat Diseases/microbiology , Goats , Humans , Leptospira/immunology , Leptospirosis/blood , Leptospirosis/immunology , Leptospirosis/microbiology , Male , Nepal/epidemiology , Prevalence , Risk Factors , Serologic Tests , Sex Factors , Young Adult , Zoonoses/microbiologyABSTRACT
Widespread resistance to first-line TB drugs is a major problem that will likely only be resolved through the development of new drugs with novel mechanisms of action. We have used structure-guided methods to develop a lead molecule that targets the thioesterase activity of polyketide synthase Pks13, an essential enzyme that forms mycolic acids, required for the cell wall of Mycobacterium tuberculosis. Our lead, TAM16, is a benzofuran class inhibitor of Pks13 with highly potent in vitro bactericidal activity against drug-susceptible and drug-resistant clinical isolates of M. tuberculosis. In multiple mouse models of TB infection, TAM16 showed in vivo efficacy equal to the first-line TB drug isoniazid, both as a monotherapy and in combination therapy with rifampicin. TAM16 has excellent pharmacological and safety profiles, and the frequency of resistance for TAM16 is â¼100-fold lower than INH, suggesting that it can be developed as a new antitubercular aimed at the acute infection. PAPERCLIP.