ABSTRACT
Extracellular vesicles (EVs) are an important regulatory factor for natural killer cell activity (NKA) in the tumor microenvironment. The relationship between circulating EVs in the peripheral blood and natural killer (NK) cells in prostate cancer (PCa) is unclear. This study aimed at investigating the key regulators in the interaction between circulating EVs and NK cells in PCa patients before and after tumor removal. NK-cell characteristics were prospectively assessed in 79 patients treated with robot-assisted laparoscopic radical prostatectomy preoperatively and postoperatively. Compared with healthy donors, the existence of prostate tumors increased the number of circulating EVs and altered ligand expression of EVs. Circulating EVs extracted from cancer patients significantly decreased NKA of NK cells compared with those extracted from healthy donors. Upon treatment with an inhibiting antibody or small interfering RNA, natural killer cell protein group 2A (NKG2A) was identified as the main NKA regulator in cancer patients for accepting the signal from circulating EVs. After surgery, NKA was increased and NKG2A expression on NK cells was significantly reduced. The expression of ligands for natural killer cell protein group 2D (NKG2D) on EVs and the level of circulation EVs both significantly increased. With the decrease in NKG2A levels on NK cells and the increase in total NKG2D ligands on circulating EVs, which was increased postoperatively, both NKG2A on NK cells and NKG2D ligands on circulating exosomes are main regulators of NKA restoration after prostatectomy.
Subject(s)
Extracellular Vesicles , Prostatic Neoplasms , Male , Humans , NK Cell Lectin-Like Receptor Subfamily K/metabolism , Ligands , Killer Cells, Natural/metabolism , Extracellular Vesicles/metabolism , Prostatic Neoplasms/pathology , Prostatectomy , Tumor MicroenvironmentABSTRACT
BACKGROUND: Diabetic cardiomyopathy (DC) is one of the major lethal complications in patients with diabetes mellitus (DM); however, no specific strategy for preventing or treating DC has been identified. PURPOSE: This study aimed to investigate the effects of ß-lapachone (Lap), a natural compound that increases antioxidant activity in various tissues, on DC and explore the underlying mechanisms. STUDY DESIGN AND METHODS: As an in vivo model, C57BL/6 mice were fed with the high-fat diet (HF) for 10 weeks to induce type 2 DM. Mice were fed Lap with the HF or after 5 weeks of HF treatment to investigate the protective effects of Lap against DC. RESULTS: In the two in vivo models, Lap decreased heart weight, increased heart function, reduced oxidative stress, and elevated mitochondrial content under the HF. In the in vitro model, palmitic acid (PA) was used to mimic the effects of an HF on the differentiated-cardiomyoblast cell line H9c2. The results demonstrated that Lap reduced PA-induced ROS production by increasing the expression of antioxidant regulators and enzymes, inhibiting inflammation, increasing mitochondrial activity, and thus reducing cell damage. Via the use of specific inhibitors and siRNA, the protective effects of Lap were determined to be mediated mainly by NQO1, Sirt1 and mitochondrial activity. CONCLUSION: Heart damage in DM is usually caused by excessive oxidative stress. This study showed that Lap can protect the heart from DC by upregulating antioxidant ability and mitochondrial activity in cardiomyocytes. Lap has the potential to serve as a novel therapeutic agent for both the prevention and treatment of DC.
Subject(s)
Diabetes Mellitus , Diabetic Cardiomyopathies , Naphthoquinones , Animals , Antioxidants/metabolism , Antioxidants/pharmacology , Diabetic Cardiomyopathies/drug therapy , Diabetic Cardiomyopathies/metabolism , Mice , Mice, Inbred C57BL , Mitochondria , NAD(P)H Dehydrogenase (Quinone)/metabolism , Naphthoquinones/pharmacology , Oxidative StressABSTRACT
BACKGROUND: Cisplatin (CDDP) is a first-line chemotherapeutic drug for treating various cancers. However, CDDP also damages normal cells and causes many side effects. Recently, CDDP has been demonstrated to kill cancer cells by targeting mitochondria. Protecting mitochondria might be a potential therapeutic strategy for CDDP-induced side effects. ß-Lapachone (ß-lap), a recognized NAD+ booster, has been reported to regulate mitochondrial activity. However, it remains unclear whether maintaining mitochondrial activity is the key factor in the protective effects of ß-lap in CDDP-treated normal cells. PURPOSE: In this study, the protective effects of ß-lap on mitochondria against CDDP cytotoxicity in normal cells were evaluated. STUDY DESIGN: In vitro cell models were used in this study, including 3T3 fibroblasts, human dermal fibroblasts, MCF-7 breast cancer cells, and MDA-MB-231 breast cancer cells. METHODS: Cells were treated with CDDP and ß-lap, and cell survival, NAD+, mitochondrial activity, autophagy, and ATP production were measured. Various inhibitors and siRNAs were used to confirm the key signal underlying the protective effects of ß-lap. RESULTS: The results demonstrated that ß-lap significantly decreased CDDP cytotoxicity in normal fibroblasts. With various inhibitors and siRNAs, ß-lap reduced CDDP-induced damage to normal fibroblasts by maintaining mitochondrial activity and increasing autophagy through the NQO1/NAD+/SIRT1 axis. Most importantly, the protective effects of ß-lap in fibroblasts did not affect the therapeutic effects of CDDP in cancer cells. This study indicated that mitochondrial activity, energy production, and NQO1 levels might be crucial responses separating normal cells from cancer cells under exposure to CDDP and ß-lap. CONCLUSION: ß-lap could be a good synergistic drug for reducing the side effects of CDDP without affecting the anticancer drug effect.
Subject(s)
Antineoplastic Agents , Breast Neoplasms , Naphthoquinones , Antineoplastic Agents/pharmacology , Cell Line, Tumor , Cisplatin/pharmacology , Female , Humans , Mitochondria , NAD , NAD(P)H Dehydrogenase (Quinone) , Naphthoquinones/pharmacologyABSTRACT
In addition to inducing apoptosis, caspase inhibition contributes to necroptosis and/or autophagy depending on the cell type and cellular context. In macrophages, necroptosis can be induced by co-treatment with Toll-like receptor (TLR) ligands (lipopolysaccharide [LPS] for TLR4 and polyinosinic-polycytidylic acid [poly I:C] for TLR3) and a cell-permeable pan-caspase inhibitor zVAD. Here, we elucidated the signaling pathways and molecular mechanisms of cell death. We showed that LPS/zVAD- and poly I:C/zVAD-induced cell death in bone marrow-derived macrophages (BMDMs) was inhibited by receptor-interacting protein kinase 1 (RIP1) inhibitor necrostatin-1 and autophagy inhibitor 3-methyladenine. Electron microscopic images displayed autophagosome/autolysosomes, and immunoblotting data revealed increased LC3II expression. Although zVAD did not affect LPS- or poly I:C-induced activation of IKK, JNK, and p38, it enhanced IRF3 and STAT1 activation as well as type I interferon (IFN) expression. In addition, zVAD inhibited ERK and Akt phosphorylation induced by LPS and poly I:C. Of note, zVAD-induced enhancement of the IRF3/IFN/STAT1 axis was abolished by necrostatin-1, while zVAD-induced inhibition of ERK and Akt was not. Our data further support the involvement of autocrine IFNs action in reactive oxygen species (ROS)-dependent necroptosis, LPS/zVAD-elicited ROS production was inhibited by necrostatin-1, neutralizing antibody of IFN receptor (IFNR) and JAK inhibitor AZD1480. Accordingly, both cell death and ROS production induced by TLR ligands plus zVAD were abrogated in STAT1 knockout macrophages. We conclude that enhanced TRIF-RIP1-dependent autocrine action of IFNß, rather than inhibition of ERK or Akt, is involved in TLRs/zVAD-induced autophagic and necroptotic cell death via the JAK/STAT1/ROS pathway.
Subject(s)
Autophagic Cell Death , Toll-Like Receptor 3 , Caspase Inhibitors/metabolism , Caspase Inhibitors/pharmacology , Caspases/metabolism , Ligands , Lipopolysaccharides/pharmacology , Macrophages , Poly I/metabolism , Proto-Oncogene Proteins c-akt/metabolism , Reactive Oxygen Species/metabolism , Toll-Like Receptor 3/metabolismABSTRACT
The taste buds and associated glands, known as von Ebner's glands (VEGs), are involved in and augment gustatory function. The obese diabetic db/db mouse, which has defects in the leptin receptor, displays enhanced neural responses to, and an elevated behavioral preference for, sweet stimuli. However, the effect of diabetes on the morphology of circumvallate papilla (CVP) taste buds and the role of VEGs have not been investigated. The present study aimed to compare the CVP taste buds and VEGs in wildtype (Wt) and type 2 diabetic (db/db) mice. These mice were divided into control and isoproterenol-treated (at 1 h, 2 h, and 4 h after one day of fasting) groups, and were sacrificed for morphometric, immunohistochemical, and ultrastructural analyses. Morphometry revealed no significant difference in papilla size and the number of taste buds in the control and diabetic groups. Detection of PGP 9.5-immunoreactivity revealed nerve fibers in the trench wall of vallate papillae, but no significant differences were detected between groups. α-Amylase immunoreactivity levels in Wt and db/db mice were also similar. However, 1 h after isoproterenol injection, the majority of the VEG secretion of db/db mice was discharged, while the level of α-amylase was restored by 2 h after injection. The effect on α-amylase was in line with the quantitative ultrastructural analysis of the secretory granules. Our findings suggest diabetic metabolic disturbances in db/db mice do not alter the structure or innervation of CVP taste buds. However, the VEG secretory pattern was altered in db/db mice and might disrupt taste sensation.
Subject(s)
Diabetes Mellitus , Taste Buds , von Ebner Glands , Animals , Diabetes Mellitus/metabolism , Mice , Mice, Inbred Strains , Taste/physiology , Tongue/innervation , Tongue/metabolismABSTRACT
Liver fibrosis is a progression of chronic liver disease characterized by excess deposition of fibrillary collagen. The aim of this study was to investigate the protective effect of a triterpenoid-enriched extract (TEE) from bitter melon leaves against carbon tetrachloride (CCl4)-induced hepatic fibrosis in mice. Male ICR mice received TEE (100 or 150 mg kg-1) by daily oral gavage for one week before starting CCl4 administration and throughout the entire experimental period. After intraperitoneal injection of CCl4 for nine weeks, serum and liver tissues of the mice were collected for biochemical, histopathological and molecular analyses. Our results showed that TEE supplementation reduced CCl4-induced serum aspartate aminotransferase and alanine aminotransferase activities. Histopathological examinations revealed that CCl4 administration results in hepatic fibrosis, while TEE supplementation significantly suppressed hepatic necroinflammation and collagen deposition. In addition, TEE supplementation decreased α-smooth muscle actin (α-SMA)-positive staining and protein levels of α-SMA and transforming growth factor-ß1. TEE-supplemented mice had lower mRNA expression levels of interleukin-6, tumor necrosis factor-α, and toll-like receptor 4. Moreover, TEE (150 mg kg-1) supplementation significantly reduced intrahepatic inflammatory Ly6C+ monocyte infiltration. We demonstrated that TEE could ameliorate hepatic fibrosis by regulating inflammatory cytokine secretion and α-SMA expression in the liver to reduce collagen accumulation.
Subject(s)
Anti-Inflammatory Agents/administration & dosage , Liver Cirrhosis/drug therapy , Momordica charantia/chemistry , Plant Extracts/administration & dosage , Triterpenes/administration & dosage , Alanine Transaminase/genetics , Alanine Transaminase/immunology , Animals , Aspartate Aminotransferases/genetics , Aspartate Aminotransferases/immunology , Carbon Tetrachloride/adverse effects , Humans , Interleukin-6/genetics , Interleukin-6/immunology , Liver/drug effects , Liver/enzymology , Liver/immunology , Liver Cirrhosis/chemically induced , Liver Cirrhosis/genetics , Liver Cirrhosis/immunology , Male , Mice , Mice, Inbred ICR , Plant Leaves/chemistry , Toll-Like Receptor 4/genetics , Toll-Like Receptor 4/immunology , Tumor Necrosis Factor-alpha/genetics , Tumor Necrosis Factor-alpha/immunologyABSTRACT
OBJECTIVES: In the past few decades, multiple-antibiotic-resistant Staphylococcus aureus has emerged and quickly spread in hospitals and communities worldwide. Additionally, the formation of antibiotic-tolerant persisters and biofilms further reduces treatment efficacy. Previously, we identified a sorafenib derivative, SC5005, with bactericidal activity against MRSA in vitro and in vivo. Here, we sought to elucidate the resistance status, mode of action and anti-persister activity of this compound. METHODS: The propensity of S. aureus to develop SC5005 resistance was evaluated by assessment of spontaneous resistance and by multi-passage selection. The mode of action of SC5005 was investigated using macromolecular synthesis, LIVE/DEAD and ATPlite assays and DiOC2(3) staining. The effect of SC5005 on the mammalian cytoplasmic membrane was measured using haemolytic and lactate dehydrogenase (LDH) assays and flow cytometry. RESULTS: SC5005 depolarized and permeabilized the bacterial cytoplasmic membrane, leading to reduced ATP production. Because of this mode of action, no resistance of S. aureus to SC5005 was observed after constant exposure to sub-lethal concentrations for 200 passages. The membrane-perturbing activity of SC5005 was specific to bacteria, as no significant haemolysis or release of LDH from human HT-29 cells was detected. Additionally, compared with other bactericidal antibiotics, SC5005 exhibited superior activity in eradicating both planktonic and biofilm-embedded S. aureus persisters. CONCLUSIONS: Because of its low propensity for resistance development and potent persister-eradicating activity, SC5005 is a promising lead compound for developing new therapies for biofilm-related infections caused by S. aureus.
Subject(s)
Methicillin-Resistant Staphylococcus aureus , Staphylococcal Infections , Animals , Anti-Bacterial Agents/pharmacology , Anti-Bacterial Agents/therapeutic use , Biofilms , Humans , Membrane Potentials , Microbial Sensitivity Tests , Staphylococcal Infections/drug therapy , Staphylococcus aureusABSTRACT
BACKGROUND/PURPOSE: The inflammatory milieu has been firmly established to affect cancer progression. However, the connection between natural killer (NK) cells and prostate cancer (PCa) has not been elucidated. METHODS: Prospective data on NK cell activity (NKA) and NK cell subset distribution patterns were evaluated from 51 patients treated with robot-assisted laparoscopic radical prostatectomy. Whole-blood samples were collected from patients preoperatively and 4-6 weeks postoperatively. The samples were subjected to NKA tests, NK cell number counts, determination of the NKG2D (activating receptor of NK cells), NKG2A (inhibiting receptor), and other surface markers. All the analyses were compared to the clinicopathological characteristics of patients. NKA was estimated by measuring interferon-γ (IFN-γ) levels after stimulation of the peripheral blood with PROMOCA™, which specifically stimulates the release of IFN-γ from NK cells. RESULTS: NKA was lower in patients with PCa than in healthy participants (484.66 vs. 1550 pg/mL). A paired comparison revealed significantly higher NKA postoperatively than preoperatively (1054 vs. 484.66 pg/mL; p = 0.011). Patients with negative surgical margins exhibited significantly higher postoperative NKA and NKA ratio (postoperative NKA/preoperative NKA) than those with positive margins (557 vs. 1921 pg/mL, p < 0.001; 3.6 vs. 1.59, p = 0.024). However, there was no difference in the postoperative NK cell number or the CD56bright/CD16-/CD3- or CD56dim/CD16+/CD3- cell numbers between the negative and positive margin groups. Postoperative NKA was significantly higher in lower-stage (1/2) than in higher-stage (3/4) PCa (1365 vs. 594 pg/mL, p = 0.014). CONCLUSION: NKA was significantly higher postoperatively than preoperatively. Patients with positive surgical margins had lower postoperative NKA than those with negative margins. Lower postoperative NKA was also observed in higher-stage PCa. NKA could be used as a supplemental marker for detecting the remaining tumor cells after prostatectomy in combination of PSA.
Subject(s)
Margins of Excision , Prostatectomy , Flow Cytometry , Humans , Killer Cells, Natural , Male , Prospective StudiesABSTRACT
Para-cresyl sulfate (P-CS), a major uremic toxin derived from the metabolites of tyrosine and phenylalanine through liver, existed in the blood of patients with chronic kidney disease (CKD). CKD increases the malignancy in bladder cancers; however, effects of P-CS on bladder cancers are not fully understood. P-CS is conjugated with BSA physiologically, and this study aims to investigate the effects and possible underlying mechanisms of BSA-bounded P-CS on human bladder cancer cells. With P-CS treatment, the intracellular ROS increased in bladder cancer cells. ROS then triggered epithelial-mesenchymal transition (EMT), stress fiber redistribution, and cell migration. With specific inhibitors, the key signals regulating P-CS-treated migration are Src and FAK. This study provided a clinical clue that patients with higher serum P-CS have a higher risk of malignant urothelial carcinomas, and a regulatory pathway of how P-CS regulates bladder cancer migration.
Subject(s)
Epithelial-Mesenchymal Transition/drug effects , Sulfates/pharmacology , Urinary Bladder Neoplasms/metabolism , Urinary Bladder/metabolism , Cell Line, Tumor , Cell Movement/drug effects , Cell Movement/physiology , Epithelial Cells/drug effects , Epithelial-Mesenchymal Transition/physiology , Humans , Reactive Oxygen Species/metabolism , Signal Transduction/drug effects , Signal Transduction/physiology , Urinary Bladder/pathology , Urinary Bladder Neoplasms/pathology , src-Family Kinases/metabolism , src-Family Kinases/pharmacologyABSTRACT
Several pregnancy complications result from abnormal trophoblast invasion. The dichotomous effect of TGF-ß on epithelial-mesenchymal transition (EMT) between trophoblast invasion and cancer progression remains unknown and a critical concern. We attenuated the expression of TGF-ß type 1 receptor (coding by TGFBR1) with RNA interference in trophoblastic cells and significantly enhanced the trophoblastic invasion. Analysis of microRNA profiles in trophoblasts indicated microRNA-7 as a key molecule linking TGF-ß with the negative regulation of trophoblast invasion. We then attenuated TGFBR1 and miR-7 transcription by transducing either short hairpin RNA targeting TGFBR1 or anti-miR-7-locked nucleonic acid, and we observed an up-regulation of EMT-related transcription factors (TFs) and their downstream effectors, causing a mesenchymal transition of trophoblasts. Conversely, overexpression of TGFBR1 or miR-7 led to the epithelial transition of trophoblasts. Our results showed that TGF-ß-induced miR-7 expression negatively modulated the TGF-ß-SMAD family member 2-mediated EMT pathway via targeting EMT-related TFs and down-regulating their mesenchymal markers. These findings possibly explain, at least in part, why TGF-ß exerts an opposite effect on EMT during trophoblast invasion and cancer progression.-Shih, J.-C., Lin, H.-H., Hsiao, A.-C., Su, Y.-T., Tsai, S., Chien, C.-L., Kung, H.-N. Unveiling the role of microRNA-7 in linking TGF-ß-Smad-mediated epithelial-mesenchymal transition with negative regulation of trophoblast invasion.
Subject(s)
Carcinogenesis/metabolism , Epithelial-Mesenchymal Transition , MicroRNAs/metabolism , Smad Proteins/metabolism , Transforming Growth Factor beta/metabolism , Trophoblasts/metabolism , Carcinogenesis/pathology , Cell Movement , HEK293 Cells , Humans , MicroRNAs/genetics , Receptor, Transforming Growth Factor-beta Type I/metabolism , Trophoblasts/pathology , Trophoblasts/physiologyABSTRACT
Loss of skeletal muscle mass and strength is often associated with disability and poor quality of life. Selective Androgen Receptor Modulators (SARMs) are under development as potential treatment. This study aims at examining the potential of wild bitter gourd (BG) as a SARM and its effects on the muscle decline induced by orchiectomy. In the cell-based androgen receptor (AR) transactivation assay, the BGP extract showed weak agonistic and antagonistic activities, resembling those of some SARMs. Male C57BL/6J mice were sham-operated (Sham group) or castrated (Cast groups) and fed a modified AIN-93G high sucrose diet supplemented without (Cast group) or with 5% lyophilized BG powder (Cast + BGP) or with testosterone propionate (7 mg TP per kg diet, Cast + TP) for 23 weeks. In contrast to the Cast + TP group, the BGP supplementation did not affect the serum testosterone concentration, and prostate and seminal vesicle mass. Both TP and BGP supplementation increased the weight of androgen responsive muscles, bulbocavernosus (BC) and levator ani (LA) (p < 0.05). The grip strength and the performance on a rotarod of the Cast + BGP group were comparable to those of the Cast + TP group (p > 0.05). The number of succinate dehydrogenase (SDH)-positive fibers of the Cast + BGP group was not significantly different from that of the Sham and Cast + TP groups (p > 0.05). The BGP supplementation up-regulated the Pgc1α, Ucp2 or Ucp3 gene expressions in skeletal muscles of castrated mice (p < 0.05). BGP showed some characteristics of the SARM and might improve skeletal muscle function through the up-regulation of mitochondrial biogenic genes and oxidative capacity, and ameliorated the castration-induced decline of skeletal muscle function in mice.
Subject(s)
Androgens/metabolism , Momordica charantia/metabolism , Muscle, Skeletal/physiopathology , Muscular Atrophy/diet therapy , Orchiectomy , Receptors, Androgen/metabolism , Androgens/chemistry , Animals , Diet Therapy , Humans , Male , Mice , Mice, Inbred C57BL , Momordica charantia/chemistry , Muscle Strength , Muscle, Skeletal/surgery , Testosterone/bloodABSTRACT
Although a vesicular nucleocytoplasmic transport system is believed to exist in eukaryotic cells, the features of this pathway are mostly unknown. Here, we report that the BFRF1 protein of the Epstein-Barr virus improves vesicular transport of nuclear envelope (NE) to facilitate the translocation and clearance of nuclear components. BFRF1 expression induces vesicles that selectively transport nuclear components to the cytoplasm. With the use of aggregation-prone proteins as tools, we found that aggregated nuclear proteins are dispersed when these BFRF1-induced vesicles are formed. BFRF1-containing vesicles engulf the NE-associated aggregates, exit through from the NE, and putatively fuse with autophagic vacuoles. Chemical treatment and genetic ablation of autophagy-related factors indicate that autophagosome formation and autophagy-linked FYVE protein-mediated autophagic proteolysis are involved in this selective clearance of nuclear proteins. Remarkably, vesicular transport, elicited by BFRF1, also attenuated nuclear aggregates accumulated in neuroblastoma cells. Accordingly, induction of NE-derived vesicles by BFRF1 facilitates nuclear protein translocation and clearance, suggesting that autophagy-coupled transport of nucleus-derived vesicles can be elicited for nuclear component catabolism in mammalian cells.-Liu, G.-T., Kung, H.-N., Chen, C.-K., Huang, C., Wang, Y.-L., Yu, C.-P., Lee, C.-P. Improving nuclear envelope dynamics by EBV BFRF1 facilitates intranuclear component clearance through autophagy.
Subject(s)
Autophagy , Membrane Proteins/metabolism , Nuclear Envelope/metabolism , Viral Proteins/metabolism , Active Transport, Cell Nucleus , Autophagosomes/metabolism , HeLa Cells , Humans , Membrane Proteins/genetics , Viral Proteins/geneticsABSTRACT
The pseudobranchs of two euryhaline teleost species, the milkfish (Chanos chanos) and the Mozambique tilapia (Oreochromis mossambicus), were studied after acclimization to different salinities using optical and electron microscopy. The milkfish pseudobranch was the lamellae-free type, with separate lamellae along the filaments containing two groups of mitochondria (Mt)-rich cells: chloride cells (CCs) and pseudobranch type cells (PSCs). Conversely, the tilapia pseudobranch was the embedded type, covered with connective tissues and with only one group of Mt-rich PSCs. Chloride cells were identified according to the apical openings and branched tubular networks around randomly distributed and diversely shaped Mt. Pseudobranchs type cells, however, were characterized according to the orderly arrangement of parallel tubules around closely packed Mt; both the tubules and the Mt were distributed in the vascular side of the cell, but were absent from the apical region. Compared with those of seawater (SW)-acclimated milkfish, the pseudobranchial lamellae of freshwater (FW) specimens were longer on average, and the Mt of the CCs had fewer cristae, were less electron-dense, and were often vacuolated. The Mt in the PSCs of FW-acclimated milkfish and tilapia were larger and more electron-dense than those of their SW-acclimated counterparts; in addition, more tubules were found to aggregately surround the Mt and basolateral membranes in the PSCs of fish from the hypo-osmotic environment. Conversely, the PSCs of tilapia were periodic acid-Schiff (PAS)-positive, and Mt in PSCs were concentrated with more parallel arrays of the tubule system than those of milkfish. Therefore, salinity-dependent changes in the ultrastructures of PSCs suggest their potential role in energy metabolism of both lamellae-free and embedded pseudobranchs, whereas the PAS-positive staining characteristics suggest a role in releasing or storaging polysaccharides in the embedded pseudobranch. J. Morphol. 278:390-402, 2017. © 2017 Wiley Periodicals, Inc.
Subject(s)
Fishes/physiology , Mitochondria/physiology , Salt Tolerance , Animals , Fresh Water , Gills/cytology , Gills/physiology , Gills/ultrastructure , Salinity , SeawaterABSTRACT
UNLABELLED: The cellular endosomal sorting complex required for transport (ESCRT) was recently found to mediate important morphogenesis processes at the nuclear envelope (NE). We previously showed that the Epstein-Barr virus (EBV) BFRF1 protein recruits the ESCRT-associated protein Alix to modulate NE structure and promote EBV nuclear egress. Here, we uncover new cellular factors and mechanisms involved in this process. BFRF1-induced NE vesicles are similar to those observed following EBV reactivation. BFRF1 is ubiquitinated, and elimination of possible ubiquitination by either lysine mutations or fusion of a deubiquitinase hampers NE-derived vesicle formation and virus maturation. While it interacts with multiple Nedd4-like ubiquitin ligases, BFRF1 preferentially binds Itch ligase. We show that Itch associates with Alix and BFRF1 and is required for BFRF1-induced NE vesicle formation. Our data demonstrate that Itch, ubiquitin, and Alix control the BFRF1-mediated modulation of the NE and EBV maturation, uncovering novel regulatory mechanisms of nuclear egress of viral nucleocapsids. IMPORTANCE: The nuclear envelope (NE) of eukaryotic cells not only serves as a transverse scaffold for cellular processes, but also as a natural barrier for most DNA viruses that assemble their nucleocapsids in the nucleus. Previously, we showed that the cellular endosomal sorting complex required for transport (ESCRT) machinery is required for the nuclear egress of EBV. Here, we further report the molecular interplay among viral BFRF1, the ESCRT adaptor Alix, and the ubiquitin ligase Itch. We found that BFRF1-induced NE vesicles are similar to those observed following EBV reactivation. The lysine residues and the ubiquitination of BFRF1 regulate the formation of BFRF1-induced NE-derived vesicles and EBV maturation. During the process, a ubiquitin ligase, Itch, preferably associates with BFRF1 and is required for BFRF1-induced NE vesicle formation. Therefore, our data indicate that Itch, ubiquitin, and Alix control the BFRF1-mediated modulation of the NE, suggesting novel regulatory mechanisms for ESCRT-mediated NE modulation.
Subject(s)
Herpesvirus 4, Human/physiology , Host-Pathogen Interactions , Membrane Proteins/metabolism , Nuclear Envelope/metabolism , Repressor Proteins/metabolism , Ubiquitin-Protein Ligases/metabolism , Viral Proteins/metabolism , Virus Assembly , Virus Replication , HeLa Cells , HumansABSTRACT
Hypoxia leads to reactive oxygen species (ROS) imbalance, which is proposed to associate with drug resistance and oncogenesis. Inhibition of enzymes of antioxidant balancing system in tumor cells was shown to reduce chemoresistance under hypoxia. However, the underlying mechanism remains unknown. The key regulator of antioxidant balancing system is nuclear factor erythroid 2-related factor 2 (NFE2L2, Nrf2). In this study, we showed that hypoxia induced ROS production and increased the Nrf2 activity. Nrf2 activation increased levels of its downstream target antioxidant enzymes, including GCLC and GCLM. The Nrf2-overexpressing also confers chemo-resistant MCF7 cells under normoxia. The in vivo mouse model also demonstrated that the chemical inhibition of Nrf2 can increase cisplatin (CDDP) cytotoxicity. Together, these results showed that Nrf2 serves as a key regulator in chemotherapeutic resistance under hypoxia through ROS-Nrf2-GCLC-GSH pathway. Therefore, targeting Nrf2 can be a potential treatment for hypoxia-induced drug resistance in breast cancer cells.
Subject(s)
Breast Neoplasms/pathology , Cisplatin/pharmacology , Drug Resistance, Neoplasm , Gene Expression Regulation, Neoplastic , Glutamate-Cysteine Ligase/metabolism , Hypoxia/physiopathology , NF-E2-Related Factor 2/metabolism , Animals , Antineoplastic Agents/pharmacology , Apoptosis , Biomarkers, Tumor/genetics , Biomarkers, Tumor/metabolism , Breast Neoplasms/drug therapy , Breast Neoplasms/metabolism , Cell Proliferation , Female , Glutamate-Cysteine Ligase/genetics , Humans , Mice , Mice, Inbred ICR , NF-E2-Related Factor 2/genetics , Signal Transduction , Tumor Cells, Cultured , Xenograft Model Antitumor AssaysABSTRACT
Arecoline, a major alkaloid in areca nuts, is involved in the pathogenesis of oral diseases. Mammalian taste buds are the structural unit for detecting taste stimuli in the oral cavity. The effects of arecoline on taste bud morphology are poorly understood. Arecoline was injected intraperitoneally (IP) into C57BL/6 mice twice daily for 1-4 weeks. After arecoline treatment, the vallate papillae were processed for electron microscopy and immunohistochemistry analysis of taste receptor proteins (T1R2, T1R3, T1R1, and T2R) and taste associated proteins (α-gustducin, PLCß2, and SNAP25). Body weight, food intake and water consumption were recorded. A 2-bottle preference test was also performed. The results demonstrated that 1) arecoline treatment didn't change the number and size of the taste buds or taste bud cells, 2) electron microscopy revealed the change of organelles and the accumulation of autophagosomes in type II cells, 3) immunohistochemistry demonstrated a decrease of taste receptor T1R2- and T1R3-expressing cells, 4) the body weight and food intake were markedly reduced, and 5) the sweet preference behavior was reduced. We concluded that the long-term injection of arecoline alters the morphology of type II taste bud cells, retards the growth of mice, and affects discrimination competencies for sweet tastants.
Subject(s)
Arecoline/pharmacology , Discrimination Learning/drug effects , Food Preferences/drug effects , Taste Buds/cytology , Taste Buds/drug effects , Taste/drug effects , Weight Loss/drug effects , Animals , Arecoline/administration & dosage , Cell Shape/drug effects , Eating/drug effects , Immunohistochemistry , Mice , Mice, Inbred C57BL , Receptors, G-Protein-Coupled/metabolism , Taste/physiologyABSTRACT
Although a standardized approach to radiotherapy has been used to treat breast cancer, regardless of subtype (e.g., luminal, basal), recent clinical data suggest that radiation response may vary significantly among subtypes. We hypothesized that this clinical variability may be due, in part, to differences in cellular radiation response. In this study, we utilized RNA samples for microarray analysis from two sources: 1. Paired pre- and postirradiation breast tumor tissue from 32 early-stage breast cancer patients treated in our unique preoperative radiation Phase I trial; and 2. Sixteen biologically diverse breast tumor cell lines exposed to 0 and 5 Gy irradiation. The transcriptome response to radiation exposure was derived by comparing gene expression in samples before and after irradiation. Genes with the highest coefficient of variation were selected for further evaluation and validated at the RNA and protein level. Gene editing and agonistic antibody treatment were performed to assess the impact of gene modulation on radiation response. Gene expression in our cohort of luminal breast cancer patients was distinctly different before and after irradiation. Further, two distinct patterns of gene expression were observed in our biologically diverse group of breast cancer cell lines pre- versus postirradiation. Cell lines that showed significant change after irradiation were largely luminal subtype, while gene expression in the basal and HER2+ cell lines was minimally impacted. The 100 genes with the most significant response to radiation in patients were identified and analyzed for differential patterns of expression in the radiation-responsive versus nonresponsive cell lines. Fourteen genes were identified as significant, including FAS, a member of the tumor necrosis factor receptor family known to play a critical role in programed cell death. Modulation of FAS in breast cancer cell lines altered radiation response phenotype and enhanced radiation sensitivity in radioresistant basal cell lines. Our findings suggest that cell-type-specific, radiation-induced FAS contributes to subtype-specific breast cancer radiation response and that activation of FAS pathways may be exploited for biologically tailored radiotherapy.
Subject(s)
Biomarkers, Tumor/genetics , Breast Neoplasms/genetics , Breast Neoplasms/radiotherapy , Molecular Targeted Therapy , Radiation Tolerance/genetics , fas Receptor/genetics , Biomarkers, Tumor/metabolism , Breast Neoplasms/pathology , Cell Line, Tumor , Female , Genes, p53/genetics , Humans , Middle Aged , Oligonucleotide Array Sequence Analysis , Phenotype , Protein Transport/radiation effects , Transcriptional Activation/radiation effects , Transcriptome/radiation effects , fas Receptor/metabolismABSTRACT
The areca nut-chewing habit is common in Southeast Asia, India, and Taiwan, and arecoline is the most abundant and potent component in the areca nut. The effects of arecoline on birth defects have been explored in many species, including chicken, mice, and zebrafish. The effects of arecoline on embryos after long-term exposure are well established; however, the effects of short-term embryo exposure to arecoline are not understood. Using zebrafish, we study the effects of short-term exposure of arecoline on embryos to model the human habit of areca nut-chewing during early pregnancy. Arecoline, at concentrations from 0.001% to 0.04%, was administered to zebrafish embryos from 4 to 24 hours post fertilization. The morphological changes, survival rates, body length, and skeletal muscle fiber structure were then investigated by immunohistochemistry, confocal microscopy, and conventional electron microscopy. With exposure of embryos to increasing arecoline concentrations, we observed a significant decline in the hatching and survival rates, general growth retardation, lower locomotor activity, and swimming ability impairment. Immunofluorescent staining demonstrated a loose arrangement of myosin heavy chains, and ultrastructural observations revealed altered myofibril arrangement and swelling of the mitochondria. In addition, the results of flow-cytometry and JC-1 staining to assay mitochondria activity, as well as reverse transcription-polymerase chain reaction analyses of functional gene expression, revealed mitochondrial dysfunctions after exposure to arecoline. We confirmed that short-term arecoline exposure resulted in retarded embryonic development and decreased locomotor activity due to defective somitic skeletal muscle development and mitochondrial dysfunction.
Subject(s)
Arecoline/toxicity , Cholinergic Agonists/toxicity , Embryo, Nonmammalian/drug effects , Zebrafish/physiology , Animals , Female , Humans , Models, Animal , Motor Activity/drug effects , Muscle Fibers, Skeletal/drug effects , Pregnancy , Zebrafish/embryology , Zebrafish/growth & development , Zebrafish Proteins/genetics , Zebrafish Proteins/metabolismABSTRACT
BACKGROUND: Glioma is the most malignant tumor of the central nervous system. Efforts on the development of new chemotherapy are mandatory. Andrographolide (AND), a diterpenoid lactone isolated from the Andrographis paniculata, has been shown to have antitumor activities in several types of cancer cells. Whether AND can exert its antitumor activity in glioblastoma cells remains unknown. This study examined the anticancer effects of AND, both in vitro and in vivo. METHODS: Cell apoptosis was assayed by flow cytometry and nuclear staining. The signaling pathway for AND was determined by western blotting. The effects of AND on tumor growth was evaluated in a mouse model. RESULTS AND CONCLUSION: In vitro, with application of specific inhibitors and siRNA, AND-induced apoptosis was proven through ROS-ERK-P53-caspase 7-PARP signaling pathway. In vivo, AND significantly retarded tumor growth and caused regression of well-formed tumors in vivo. Furthermore, AND did not induce apoptosis or activate ERK and p53 in primary cultured astrocyte cells, and it may serve as a potential therapeutic candidate for the treatment of glioma.