ABSTRACT
Iron contributes to tumor initiation and progression; however, excessive intracellular free Fe2+ can be toxic to cancer cells. Our findings confirmed that multiple myeloma (MM) cells exhibited elevated intracellular iron levels and increased ferritin, a key protein for iron storage, compared with normal cells. Interestingly, Bortezomib (BTZ) was found to trigger ferritin degradation, increase free intracellular Fe2+, and promote ferroptosis in MM cells. Subsequent mechanistic investigation revealed that BTZ effectively increased NCOA4 levels by preventing proteasomal degradation in MM cells. When we knocked down NCOA4 or blocked autophagy using chloroquine, BTZ-induced ferritin degradation and the increase in intracellular free Fe2+ were significantly reduced in MM cells, confirming the role of BTZ in enhancing ferritinophagy. Furthermore, the combination of BTZ with RSL-3, a specific inhibitor of GPX4 and inducer of ferroptosis, synergistically promoted ferroptosis in MM cell lines and increased cell death in both MM cell lines and primary MM cells. The induction of ferroptosis inhibitor liproxstatin-1 successfully counteracted the synergistic effect of BTZ and RSL-3 in MM cells. Altogether, our findings reveal that BTZ elevates intracellular free Fe2+ by enhancing NCOA4-mediated ferritinophagy and synergizes with RSL-3 by increasing ferroptosisin MM cells.
Subject(s)
Bortezomib , Drug Synergism , Ferritins , Ferroptosis , Iron , Multiple Myeloma , Nuclear Receptor Coactivators , Humans , Multiple Myeloma/metabolism , Multiple Myeloma/drug therapy , Multiple Myeloma/pathology , Nuclear Receptor Coactivators/metabolism , Nuclear Receptor Coactivators/genetics , Bortezomib/pharmacology , Ferritins/metabolism , Ferroptosis/drug effects , Iron/metabolism , Cell Line, Tumor , Autophagy/drug effects , Antineoplastic Agents/pharmacology , CarbolinesABSTRACT
Vaccinia mature virus requires A26 envelope protein to mediate acid-dependent endocytosis into HeLa cells in which we hypothesized that A26 protein functions as an acid-sensitive membrane fusion suppressor. Here, we provide evidence showing that N-terminal domain (aa1-75) of A26 protein is an acid-sensitive region that regulates membrane fusion. Crystal structure of A26 protein revealed that His48 and His53 are in close contact with Lys47, Arg57, His314 and Arg312, suggesting that at low pH these His-cation pairs could initiate conformational changes through protonation of His48 and His53 and subsequent electrostatic repulsion. All the A26 mutant mature viruses that interrupted His-cation pair interactions of His48 and His 53 indeed have lost virion infectivity. Isolation of revertant viruses revealed that second site mutations caused frame shifts and premature termination of A26 protein such that reverent viruses regained cell entry through plasma membrane fusion. Together, we conclude that viral A26 protein functions as an acid-sensitive fusion suppressor during vaccinia mature virus endocytosis.
Subject(s)
Endocytosis , Membrane Fusion , Vaccinia virus/metabolism , Viral Proteins/metabolism , Virus Internalization , Animals , Chlorocebus aethiops , HeLa Cells , Humans , Hydrogen-Ion Concentration , Mice , Vaccinia virus/genetics , Viral Proteins/geneticsABSTRACT
Phytoplasmas are bacterial plant pathogens which can induce severe symptoms including dwarfism, phyllody and virescence in an infected plant. Because phytoplasmas infect many important crops such as peanut and papaya they have caused serious agricultural losses. The phytoplasmal effector causing phyllody 1 (PHYL1) is an important phytoplasmal pathogenic factor which affects the biological function of MADS transcription factors by interacting with their K (keratin-like) domain, thus resulting in abnormal plant developments such as phyllody. Until now, lack of information on the structure of PHYL1 has prevented a detailed understanding of the binding mechanism between PHYL1 and the MADS transcription factors. Here, we present the crystal structure of PHYL1 from peanut witches'-broom phytoplasma (PHYL1PnWB ). This protein was found to fold into a unique α-helical hairpin with exposed hydrophobic residues on its surface that may play an important role in its biological function. Using proteomics approaches, we propose a binding mode of PHYL1PnWB with the K domain of the MADS transcription factor SEPALLATA3 (SEP3_K) and identify the residues of PHYL1PnWB that are important for this interaction. Furthermore, using surface plasmon resonance we measure the binding strength of PHYL1PnWB proteins to SEP3_K. Lastly, based on confocal images, we found that α-helix 2 of PHYL1PnWB plays an important role in PHYL1-mediated degradation of SEP3. Taken together, these results provide a structural understanding of the specific binding mechanism between PHYL1PnWB and SEP3_K.
Subject(s)
Bacterial Proteins/chemistry , MADS Domain Proteins/metabolism , Phytoplasma/chemistry , Plant Proteins/metabolism , Bacterial Proteins/genetics , Bacterial Proteins/metabolism , Cross-Linking Reagents/chemistry , Crystallography, X-Ray , Host-Pathogen Interactions/physiology , Hydrophobic and Hydrophilic Interactions , MADS Domain Proteins/chemistry , MADS Domain Proteins/genetics , Multiprotein Complexes/chemistry , Mutation , Phytoplasma/pathogenicity , Plant Diseases/microbiology , Plant Proteins/chemistry , Plant Proteins/genetics , Protein Interaction Domains and MotifsABSTRACT
We report experimental and computational studies investigating the effects of three osmolytes, trimethylamine N-oxide (TMAO), betaine, and glycine, on the hydrophobic collapse of an elastin-like polypeptide (ELP). All three osmolytes stabilize collapsed conformations of the ELP and reduce the lower critical solution temperature (LSCT) linearly with osmolyte concentration. As expected from conventional preferential solvation arguments, betaine and glycine both increase the surface tension at the air-water interface. TMAO, however, reduces the surface tension. Atomically detailed molecular dynamics (MD) simulations suggest that TMAO also slightly accumulates at the polymer-water interface, whereas glycine and betaine are strongly depleted. To investigate alternative mechanisms for osmolyte effects, we performed FTIR experiments that characterized the impact of each cosolvent on the bulk water structure. These experiments showed that TMAO red-shifts the OH stretch of the IR spectrum via a mechanism that was very sensitive to the protonation state of the NO moiety. Glycine also caused a red shift in the OH stretch region, whereas betaine minimally impacted this region. Thus, the effects of osmolytes on the OH spectrum appear uncorrelated with their effects upon hydrophobic collapse. Similarly, MD simulations suggested that TMAO disrupts the water structure to the least extent, whereas glycine exerts the greatest influence on the water structure. These results suggest that TMAO stabilizes collapsed conformations via a mechanism that is distinct from glycine and betaine. In particular, we propose that TMAO stabilizes proteins by acting as a surfactant for the heterogeneous surfaces of folded proteins.
Subject(s)
Betaine/chemistry , Elastin/chemistry , Glycine/chemistry , Methylamines/chemistry , Peptides/chemistry , Air/analysis , Hydrophobic and Hydrophilic Interactions , Molecular Dynamics Simulation , Osmotic Pressure , Protein Folding , Solutions , Surface Tension , Water/chemistryABSTRACT
It is widely believed that a significant portion of the gut microbiota, which play crucial roles in overall health and disease, originates from the food we consume. Sashimi is a type of popular raw seafood cuisine. Its microbiome, however, remained to be thoroughly explored. The objective of this study is to explore the microbiome composition in sashimi at the time when it is served and ready to be eaten. Specifically, our tasks include investigating the diversity and characteristics of microbial profiles in sashimi with respect to the fish types. We utilized the Sanger-sequencing based DNA barcoding technology for fish species authentication and next-generation sequencing for sashimi microbiome profiling. We investigated the microbiome profiles of amberjack, cobia, salmon, tuna and tilapia sashimi, which were all identified using the MT-CO1 DNA sequences regardless of their menu offering names. Chao1 and Shannon indexes, as well as Bray-Curtis dissimilarity index were used to evaluate the alpha and beta diversities of sashimi microbiome. We successfully validated our previous observation that tilapia sashimi has a significantly higher proportions of Pseudomonas compared to other fish sashimi, using independent samples (P = 0.0010). Salmon sashimi exhibited a notably higher Chao1 index in its microbiome in contrast to other fish species (P = 0.0031), indicating a richer and more diverse microbial ecosystem. Non-Metric Multidimensional Scaling (NMDS) based on Bray-Curtis dissimilarity index revealed distinct clusters of microbiome profiles with respect to fish types. Microbiome similarity was notably observed between amberjack and tuna, as well as cobia and salmon. The relationship of microbiome similarity can be depicted as a tree which resembles partly the phylogenetic tree of host species, emphasizing the close relationship between host evolution and microbial composition. Moreover, salmon exhibited a pronounced relative abundance of the Photobacterium genus, significantly surpassing tuna (P = 0.0079), observed consistently across various restaurant sources. In conclusion, microbiome composition of Pseudomonas is significantly higher in tilapia sashimi than in other fish sashimi. Salmon sashimi has the highest diversity of microbiome among all fish sashimi that we analyzed. The level of Photobacterium is significantly higher in salmon than in tuna across all the restaurants we surveyed. These findings provide critical insights into the intricate relationship between the host evolution and the microbial composition. These discoveries deepen our understanding of sashimi microbiota, facilitating our decision in selecting raw seafood.
Subject(s)
Gastrointestinal Microbiome , Microbiota , Animals , Phylogeny , Microbiota/genetics , Gastrointestinal Microbiome/genetics , Salmon , Tuna/genetics , Seafood , Photobacterium , PseudomonasABSTRACT
The coronavirus disease 2019 (COVID-19) pandemic has had a major impact on human life. This review highlights the versatile roles of both classical and modern structure-based approaches for COVID-19. X-ray crystallography, nuclear magnetic resonance spectroscopy, and cryogenic electron microscopy are the three cornerstones of classical structural biology. These technologies have helped provide fundamental and detailed knowledge regarding severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and the related human host proteins as well as enabled the identification of its target sites, facilitating the cessation of its transmission. Further progress into protein structure modeling was made using modern structure-based approaches derived from homology modeling and integrated with artificial intelligence (AI), facilitating advanced computational simulation tools to actively guide the design of new vaccines and the development of anti-SARS-CoV-2 drugs. This review presents the practical contributions and future directions of structure-based approaches for COVID-19.
Subject(s)
COVID-19 , Humans , SARS-CoV-2 , Artificial Intelligence , COVID-19 Vaccines , Computer SimulationABSTRACT
COVID-19 has greatly affected human life for over 3 years. In this review, we focus on smart healthcare solutions that address major requirements for coping with the COVID-19 pandemic, including (1) the continuous monitoring of severe acute respiratory syndrome coronavirus 2, (2) patient stratification with distinct short-term outcomes (eg, mild or severe diseases) and long-term outcomes (eg, long COVID), and (3) adherence to medication and treatments for patients with COVID-19. Smart healthcare often utilizes medical artificial intelligence (AI) and cloud computing and integrates cutting-edge biological and optoelectronic techniques. These are valuable technologies for addressing the unmet needs in the management of COVID. By leveraging deep learning/machine learning capabilities and big data, medical AI can perform precise prognosis predictions and provide reliable suggestions for physicians' decision-making. Through the assistance of the Internet of Medical Things, which encompasses wearable devices, smartphone apps, internet-based drug delivery systems, and telemedicine technologies, the status of mild cases can be continuously monitored and medications provided at home without the need for hospital care. In cases that develop into severe cases, emergency feedback can be provided through the hospital for rapid treatment. Smart healthcare can possibly prevent the development of severe COVID-19 cases and therefore lower the burden on intensive care units.
Subject(s)
COVID-19 , Humans , Artificial Intelligence , Post-Acute COVID-19 Syndrome , Pandemics/prevention & control , Delivery of Health CareABSTRACT
The abuse of antibiotics has led to the emergence of multidrug-resistant microbial pathogens, presenting a pressing challenge in global healthcare. Membrane-disrupting antimicrobial peptides (AMPs) combat so-called superbugs via mechanisms different than conventional antibiotics and have good application prospects in medicine, agriculture, and the food industry. However, the mechanism-of-action of AMPs has not been fully characterized at the cellular level due to a lack of high-resolution imaging technologies that can capture cellular-membrane disruption events in the hydrated state. Previously, we reported PepD2M, a de novo-designed AMP with potent and wide-spectrum bactericidal and fungicidal activity. In this study, we use cryo-electron tomography (cryo-ET) and high-speed atomic force microscopy (HS-AFM) to directly visualize the pepD2M-induced disruption of the outer and inner membranes of the Gram-negative bacterium Escherichia coli, and compared with a well-known pore-forming peptide, melittin. Our high-resolution cryo-ET images reveal how pepD2M disrupts the E. coli membrane using a carpet/detergent-like mechanism. Our studies reveal the direct membrane-disrupting consequence of AMPs on the bacterial membrane by cryo-ET, and this information provides critical insights into the mechanisms of this class of antimicrobial agents.
Subject(s)
Antimicrobial Peptides , Electron Microscope Tomography , Escherichia coli , Cell Physiological Phenomena , Anti-Bacterial Agents/pharmacologyABSTRACT
Cyclic di-GMP (c-di-GMP) is a novel secondary-messenger molecule that is involved in regulating a plethora of important bacterial activities through binding to an unprecedented array of effectors. Proteins with a canonical PilZ domain that bind c-di-GMP play crucial roles in regulating flagellum-based motility. In contrast, noncanonical type II PilZ domains that do not effectively bind c-di-GMP regulate twitching motility, which is dependent on type IV pili (T4P). Recent data indicate that T4P biogenesis is initiated via the interaction of a noncanonical type II PilZ protein with the GGDEF/EAL-domain protein FimX and the pilus motor protein PilB at high c-di-GMP concentrations. However, the molecular details of such interactions remain to be elucidated. In this manuscript, the first hetero-complex crystal structure between a type II PilZ protein and the EAL domain of the FimX protein (FimX(EAL)) from Xanthomonas campestris pv. campestris (Xcc) in the presence of c-di-GMP is reported. This work reveals two novel conformations of monomeric c-di-GMP in the XccFimX(EAL)-c-di-GMP and XccFimX(EAL)-c-di-GMP-XccPilZ complexes, as well as a unique interaction mode of a type II PilZ domain with FimX(EAL). These findings indicate that c-di-GMP is sufficiently flexible to adjust its conformation to match the corresponding recognition motifs of different cognate effectors. Together, these results represent a first step towards an understanding of how T4P biogenesis is controlled by c-di-GMP at the molecular level and also of the ability of c-di-GMP to bind to a wide variety of effectors.
Subject(s)
Bacterial Proteins/chemistry , Cyclic GMP/analogs & derivatives , Xanthomonas campestris/chemistry , Bacterial Proteins/classification , Bacterial Proteins/metabolism , Crystallography, X-Ray , Cyclic GMP/chemistry , Cyclic GMP/metabolism , Protein Binding , Protein Structure, Tertiary , Pseudomonas aeruginosa/chemistry , Sequence Homology, Amino AcidABSTRACT
c-di-GMP is a major secondary-messenger molecule in regulation of bacterial pathogenesis. Therefore, the c-di-GMP-mediated signal transduction network is of considerable interest. The PilZ domain was the first c-di-GMP receptor to be predicted and identified. However, every PilZ domain binds c-di-GMP with a different binding affinity. Intriguingly, a noncanonical PilZ domain has recently been found to serve as a mediator to link FimX(EAL) to the PilB or PilT ATPase to control the function of type IV pili (T4P). It is thus essential to determine the structure of the FimX(EAL)-PilZ complex in order to determine how the binding of c-di-GMP to the FimX(EAL) domain induces conformational change of the adjoining noncanonical PilZ domain, which may transmit information to PilB or PilT to control T4P function. Here, the preparation and preliminary X-ray diffraction studies of the XccFimX(EAL)-c-di-GMP and XccFimX(EAL)-c-di-GMP-XccPilZ complexes from Xcc (Xanthomonas campestris pv. campesteris) are reported. Detailed studies of these complexes may allow a more thorough understanding of how c-di-GMP transmits its effects through the degenerate EAL domain and the noncanonical PilZ domain.
Subject(s)
Bacterial Proteins/chemistry , Cyclic GMP/analogs & derivatives , Xanthomonas campestris/chemistry , Crystallization , Crystallography, X-Ray , Cyclic GMP/chemistry , Cyclic GMP/metabolism , Protein BindingABSTRACT
The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and its variants of concern can infect people of all ages and can cause severe diseases in children, such as encephalitis, which require intensive care. Therefore, vaccines are urgently required to prevent severe disease in all age groups. We reviewed the safety and efficacy profiles of mRNA vaccines-BNT162b2 and mRNA-1273-demonstrated by clinical trials or observed in the real world. mRNA-1273 is effective in preventing SARS-CoV-2 infection in preschool children (6 months-6 years old). Both BNT162b2 and mRNA-1273 are effective in preventing SARS-CoV-2 infection in school-aged children and adolescents, thereby preventing post-coronavirus disease (COVID) conditions. The common side effects of vaccination are pain at the injection site, fatigue, and headache. Myocarditis and pericarditis are uncommon. Monitoring post-vaccination troponin levels may help prevent severe cardiac events. The SARS-CoV-2 coronavirus mutates its genome to overcome the herd immunity provided by mass vaccinations; therefore, we may need to develop new generations of vaccines, such as those using viral nucleocapsid proteins as antigens. In conclusion, the mRNA vaccines are generally safe and effective in preventing severe diseases and hospitalization among children and adolescents.
Subject(s)
COVID-19 Vaccines , COVID-19 , Adolescent , BNT162 Vaccine , COVID-19/prevention & control , COVID-19 Vaccines/adverse effects , Child , Child, Preschool , Hospitalization , Humans , Nucleocapsid Proteins , SARS-CoV-2 , Troponin , Vaccination , Viral VaccinesABSTRACT
Pueraria lobata flower is a medicinal herb for treating intoxication, hepatic, and gastrointestinal tract lesions induced by alcohol. This study aims to investigate the isoflavonoid glycosides in P. lobata flowers. Two new isoflavone compounds were isolated from the extract of P. lobata flowers. Their structures were determined to be 5,6,7,4'-tetrahydroxyisoflavone-6,7-di-O-ß-D-glucopyranoside and 5,6,7-trihydroxy-4'-methoxyisoflavone-6,7-di-O-ß-D-glucopyranoside on the basis of spectroscopic means including HR-ESI-MS, UV, IR, ¹H, and ¹³C NMR.
Subject(s)
Drugs, Chinese Herbal/chemistry , Glycosides/isolation & purification , Isoflavones/isolation & purification , Pueraria/chemistry , Flowers/chemistry , Glycosides/chemistry , Isoflavones/chemistry , Molecular Structure , Nuclear Magnetic Resonance, Biomolecular , StereoisomerismABSTRACT
Medulloblastoma is the most common embryonic brain tumor in children. We investigated a cohort of 52 Asian medulloblastoma patients aged between 0 and 19 years old, who received surgical resections and post-resection treatments in the Taipei Medical University Hospital and the Taipei Veterans General Hospital. Genome-wide RNA sequencing was performed on fresh-frozen surgical tissues. These data were analyzed using the CIBERSORTx immune deconvolution software. Two external clinical and molecular datasets from United States (n = 62) and Canada (n = 763) were used to evaluate the transferability of the gene-signature scores across ethnic populations. The abundance of 13 genes, including DLL1, are significantly associated with overall survival (All Cox regression P < 0.001). A gene-signature score was derived from the deep transcriptome, capable of indicating patients' subsequent tumor recurrence (Hazard Ratio [HR] 1.645, confidence interval [CI] 1.337-2.025, P < 0.001) and mortality (HR 2.720, CI 1.798-4.112, P < 0.001). After the adjustment of baseline clinical factors, the score remains indicative of recurrence-free survival (HR 1.604, CI 1.292-1.992, P < 0.001) and overall survival (HR 2.781, CI 1.762-4.390, P < 0.001). Patients stratified by this score manifest not only distinct prognosis but also different molecular characteristics: Notch signaling ligands and receptors are comparatively overexpressed in patients with poorer prognosis, while tumor infiltrating natural killer cells are more abundant in patients with better prognosis. Additionally, immunohistochemical staining showed the DLL1 protein, a major ligand in the Notch signaling pathway, and the NCAM1 protein, a representative biomarker of natural killer cells, are present in the surgical tissues of patients of four molecular subgroups, WNT, SHH, Group 3 and Group 4. NCAM1 RNA level is also positively associated with the mutation burden in tumor (P = 0.023). The gene-signature score is validated successfully in the Canadian cohort (P = 0.009) as well as its three molecular subgroups (SHH, Group 3 and Group 4; P = 0.047, 0.018 and 0.040 respectively). In conclusion, pediatric medullablastoma patients can be stratified by gene-signature scores with distinct prognosis and molecular characteristics. Ligands and receptors of the Notch signaling pathway are overexpressed in the patient stratum with poorer prognosis. Tumor infiltrating natural killer cells are more abundant in the patient stratum with better prognosis.
Subject(s)
Brain Neoplasms/genetics , Brain Neoplasms/pathology , Gene Expression Regulation, Neoplastic/genetics , Gene Expression , Killer Cells, Natural/pathology , Lymphocytes, Tumor-Infiltrating/pathology , Medulloblastoma/genetics , Medulloblastoma/pathology , Receptors, Notch/genetics , Receptors, Notch/metabolism , Signal Transduction/genetics , Signal Transduction/physiology , Adolescent , Age Factors , Brain Neoplasms/surgery , CD56 Antigen/genetics , CD56 Antigen/metabolism , Calcium-Binding Proteins/genetics , Calcium-Binding Proteins/metabolism , Child , Child, Preschool , Female , Humans , Infant , Infant, Newborn , Male , Medulloblastoma/surgery , Membrane Proteins/genetics , Membrane Proteins/metabolism , Prognosis , Sequence Analysis, RNA/methods , Taiwan , Young AdultABSTRACT
Uracil-DNA glycosylases (UDGs) are conserved DNA-repair enzymes that can be found in many species, including herpesviruses. Since they play crucial roles for efficient viral DNA replication in herpesviruses, they have been considered as potential antiviral targets. In our previous work, Staphylococcus aureus SAUGI was identified as a DNA mimic protein that targets UDGs from S. aureus, human, Herpes simplex virus (HSV) and Epstein-Barr virus (EBV). Interestingly, SAUGI has the strongest inhibitory effects with EBVUDG. Here, we determined complex structures of SAUGI with EBVUDG and another γ-herpesvirus UDG from Kaposi's sarcoma-associated herpesvirus (KSHVUDG), which SAUGI fails to effectively inhibit. Structural analysis of the SAUGI/EBVUDG complex suggests that the additional interaction between SAUGI and the leucine loop may explain why SAUGI shows the highest binding capacity with EBVUDG. In contrast, SAUGI appears to make only partial contacts with the key components responsible for the compression and stabilization of the DNA backbone in the leucine loop extension of KSHVUDG. The findings in this study provide a molecular explanation for the differential inhibitory effects and binding strengths that SAUGI has on these two UDGs, and the structural basis of the differences should be helpful in developing inhibitors that would interfere with viral DNA replication.
Subject(s)
DNA Repair Enzymes/chemistry , Gammaherpesvirinae/enzymology , Uracil-DNA Glycosidase/chemistry , Amino Acid Substitution , DNA Repair Enzymes/isolation & purification , DNA Repair Enzymes/metabolism , DNA Replication , Models, Molecular , Molecular Conformation , Protein Binding , Recombinant Proteins , Structure-Activity Relationship , Uracil-DNA Glycosidase/isolation & purification , Uracil-DNA Glycosidase/metabolismABSTRACT
A previous report showed that transforming growth factor-beta1 (TGF-beta1) can induce heme oxygenase-1 (HO-1) expression, attenuate cellular injury, and maintain tissue homeostasis. In this study, we investigated the involvement of phosphoinositide-3-OH-kinase (PI3K)/Akt and the nuclear factor-kappaB (NF-kappaB) signaling pathway in TGF-beta1-induced HO-1 expression in human lung epithelial cells (A549). Treatment of A549 cells with TGF-beta1 caused HO-1 to be expressed in a concentration- and time-dependent manner. Treatment of A549 cells with LY 294002 (2-(4-morpholinyl)-8-phenyl-4H-1-benzopyran-4-one, a PI3K inhibitor), an Akt inhibitor, and the dominant negative mutant of Akt (Akt DN) inhibited TGF-beta1-induced HO-1 expression and HO-1-luciferase activity. Stimulation of cells with TGF-beta1 caused an increase in Akt phosphorylation in a time-dependent manner, which was inhibited by wortmannin and LY 294002 (PI3K inhibitors). In addition, treatment of A549 cells with Bay 117082 ((E)-3-[4-methylphenylsulfonyl]-2-propenenitrile, an IkappaB phosphorylation inhibitor), pyrrolidine dithiocarbamate (PDTC, an NF-kappaB inhibitor), and the dominant negative mutant of IkappaBalpha (IkappaBalphaM) inhibited TGF-beta1-induced HO-1 expression and HO-1-luciferase activity. Treatment of A549 cells with TGF-beta1-induced IkappaB kinase alpha/beta (IKKalpha/beta) phosphorylation, IkappaBalpha phosphorylation, IkappaBalpha degradation, p65 Ser536 phosphorylation, and kappaB-luciferase activity. The TGF-beta1-mediated increases in IKKalpha/beta phosphorylation, p65 Ser536 phosphorylation, and kappaB-luciferase activity were inhibited by LY 294002, an Akt inhibitor, and Akt DN. Taken together, these results suggest that the PI3K/Akt dependent IKKalpha/beta/NF-kappaB signaling pathway plays an important role in TGF-beta1-induced HO-1 expression in A549 cells.
Subject(s)
Heme Oxygenase-1/analysis , Lung/drug effects , NF-kappa B/physiology , Phosphatidylinositol 3-Kinases/physiology , Proto-Oncogene Proteins c-akt/physiology , Signal Transduction/physiology , Transforming Growth Factor beta1/pharmacology , Cells, Cultured , Epithelial Cells/drug effects , Epithelial Cells/enzymology , Heme Oxygenase-1/biosynthesis , Humans , I-kappa B Proteins/metabolism , Lung/enzymology , NF-KappaB Inhibitor alpha , Phosphorylation , Transcription Factor RelA/metabolismABSTRACT
DNA mimicry is a direct and effective strategy by which the mimic competes with DNA for the DNA binding sites on other proteins. Until now, only about a dozen proteins have been shown to function via this strategy, including the DNA mimic protein DMP19 from Neisseria meningitides. We have shown previously that DMP19 dimer prevents the operator DNA from binding to the transcription factor NHTF. Here, we provide new evidence that DMP19 monomer can also interact with the Neisseria nucleoid-associated protein HU. Using BS3 crosslinking, gel filtration and isothermal titration calorimetry assays, we found that DMP19 uses its monomeric form to interact with the Neisseria HU dimer. Crosslinking conjugated mass spectrometry was used to investigate the binding mode of DMP19 monomer and HU dimer. Finally, an electrophoretic mobility shift assay (EMSA) confirmed that the DNA binding affinity of HU is affected by DMP19. These results showed that DMP19 is bifunctional in the gene regulation of Neisseria through its variable oligomeric forms.
Subject(s)
Bacterial Proteins/metabolism , Histones/metabolism , Molecular Mimicry , Neisseria/metabolism , Bacterial Proteins/genetics , Dimerization , Protein BindingABSTRACT
In 2009, Typhoon Morakot struck Taiwan and caused serious harm to the indigenous peoples living in the southern mountainous regions. The objective of this study is to examine the effects of and the factors involved in individual resilience intervention of typhoon victims. Quantitative research was performed from October 2009 through September 2010. Purposive sampling yielded 77 indigenous persons who were willing to serve as participants in this study. These participants all maintained legal or actual residence in the areas of Kaohsiung that were affected by the typhoon. An individual resilience intervention program was implemented. The findings show the following: (1) after completing the individual resilience intervention program, the participants had higher individual resilience scores than before participating in the intervention program; and (2) individual resilience scores were significantly affected by residency after the typhoon. These findings suggest that an individual resilience intervention program is a useful approach that can be used to enhance the individual resilience of a victim and that professionals should pay more attention to victims who have to leave their hometowns after disasters.
Subject(s)
Cyclonic Storms , Stress Disorders, Post-Traumatic/physiopathology , Adolescent , Adult , Aged , Female , Humans , Male , Middle Aged , Taiwan , Young AdultABSTRACT
BACKGROUND: Pueraria lobata flower (Gehua) is a medicinal herb to treat intoxication, hepatic and gastrointestinal tract lesion induced by alcohol. This study aims to develop a new HPLC method for the determination of two major isoflavones in P. lobata flowers, namely tectoridin and 6"-O-xylosyl-tectoridin. METHODS: A high performance liquid chromatography (HPLC) method with a C18 column (250 mm x 4.6 mm, 5 mum) was developed for the quantitative analysis of tectoridin and 6"-O-xylosyl-tectoridin, the main isoflavone components in P. lobata flower. A simple gradient of acetonitrile/water (0 min 15:85; 35 min 50:50; 36 min 15:85; 40 min 15:85; v/v) was used, and 265 nm was selected as detection wavelength. Tectoridin and 6"-O-xylosyl-tectoridin were used as the external standards in quality control of P. lobata flower for the first time. The method was applied to practical use in quality assessment of eleven batches of P. lobata flower samples in Chinese herbal medicine market. RESULTS: The peak area response was linear for tectoridin in the 11.8-236.4 mug/mL range with a correlation coefficient of 0.9996 (P < 0.001), and for 6"-O-xylosyl-tectoridin in the 10.33-185.99 mug/mL range with a correlation coefficient of 0.9984 (P < 0.001) respectively. The average recoveries were 102.7-103.7% for tectoridin and 95.7-103.2% for 6"-O-xylosyl-tectoridin (RSDs < 3%), and the intra-day and inter-day RSDs of the two components were less than 2%. This HPLC method was applied to assess the quality of P. lobata flower from eleven provinces in China. P. lobata flowers from northern China contained 26.46-43.28 mg/g of tectoridin and 30.90-48.23 mg/g of 6"-O-xylosyl-tectoridin comparing to 10.00-19.81 mg/g of tectoridin and 11.08-37.03 mg/g of 6"-O-xylosyl-tectoridin in those from southern China. CONCLUSION: The results showed that P. lobata flowers from northern China contained more tectoridin and 6"-O-xylosyl-tectoridin than those from southern China.
ABSTRACT
In this study, we investigated the signaling pathway involved in IL-6 production caused by peptidoglycan (PGN), a cell wall component of the Gram-positive bacterium, Staphylococcus aureus, in RAW 264.7 macrophages. PGN caused concentration- and time-dependent increases in IL-6, PGE(2), and cAMP production. PGN-mediated IL-6 production was inhibited by a nonselective cyclooxygenase (COX) inhibitor (indomethacin), a selective COX-2 inhibitor (NS398), a PGE(2) (EP2) antagonist (AH6809), a PGE(4) (EP4) antagonist (AH23848), and a protein kinase A (PKA) inhibitor (KT5720), but not by a nonselective NO synthase inhibitor (N(G)-nitro-l-arginine methyl ester). Furthermore, PGE(2), an EP2 agonist (butaprost), an EP2/PGE(3) (EP3)/EP4 agonist (misoprostol), and misoprostol in the presence of AH6809 all induced IL-6 production, whereas an EP1/EP3 agonist (sulprostone) did not. PGN caused time-dependent activations of IkappaB kinase alphabeta (IKKdbeta) and p65 phosphorylation at Ser(276), and these effects were inhibited by NS398 and KT5720. Both PGE(2) and 8-bromo-cAMP also caused IKKdbeta kinase alphabeta phosphorylation. PGN resulted in two waves of the formation of NF-kappaB-specific DNA-protein complexes. The first wave of NF-kappaB activation occurred at 10-60 min of treatment, whereas the later wave occurred at 2-12 h of treatment. The PGN-induced increase in kappaB luciferase activity was inhibited by NS398, AH6809, AH23848, KT5720, a protein kinase C inhibitor (Ro31-8220), and a p38 MAPK inhibitor (SB203580). These results suggest that PGN-induced IL-6 production involves COX-2-generated PGE(2), activation of the EP2 and EP4 receptors, cAMP formation, and the activation of PKA, protein kinase C, p38 MAPK, IKKdbeta, kinase alphabeta, p65 phosphorylation, and NF-kappaB. However, PGN-induced NO release is not involved in the signaling pathway of PGN-induced IL-6 production.
Subject(s)
Cyclic AMP-Dependent Protein Kinases/physiology , Cyclooxygenase 2/physiology , I-kappa B Kinase/physiology , Interleukin-6/biosynthesis , Macrophages/immunology , NF-kappa B/physiology , Peptidoglycan/pharmacology , Receptors, Prostaglandin E/physiology , Animals , Cell Line , Cyclic AMP/biosynthesis , Cyclic AMP/physiology , Cyclic AMP-Dependent Protein Kinases/antagonists & inhibitors , Cyclic AMP-Dependent Protein Kinases/metabolism , Cyclooxygenase 2/metabolism , Cyclooxygenase 2 Inhibitors/pharmacology , Dinoprostone/antagonists & inhibitors , Dinoprostone/biosynthesis , Dinoprostone/metabolism , Dinoprostone/physiology , Enzyme Activation/drug effects , Enzyme Activation/immunology , I-kappa B Kinase/antagonists & inhibitors , I-kappa B Kinase/metabolism , Macrophages/enzymology , Macrophages/metabolism , Macrophages/microbiology , Mice , NF-kappa B/antagonists & inhibitors , NF-kappa B/metabolism , Phosphorylation , Receptors, Prostaglandin E/antagonists & inhibitors , Receptors, Prostaglandin E, EP4 Subtype , Serine/metabolism , Signal Transduction/drug effects , Signal Transduction/immunology , Staphylococcus aureus/immunology , Transcription Factor RelA/antagonists & inhibitors , Transcription Factor RelA/metabolismABSTRACT
Diabetes mellitus is a common and precarious chronic disease, which affects cellular metabolism and energy production. The condition is divided into types I and II; the most common form is type II diabetes, which is an adult-onset disease. Blood glucose testing is crucial to diabetes control, and it is effective in reducing the risk of complications and improving life quality. Unfortunately, both elderly patients and their caregivers find it difficult to monitor glucose levels long term. This study developed a communication platform for diabetes surveillance. The developed system prompts diabetics to measure their blood glucose regularly at home, and provides remote care persons with complete information about the patient's measurement. This aids in the improvement in diabetes control, thereby increasing the social activities and life quality of diabetics.