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1.
Nanoscale Horiz ; 9(8): 1372-1378, 2024 Jul 22.
Artigo em Inglês | MEDLINE | ID: mdl-38895819

RESUMO

Graphene modulators are considered a potential solution for achieving high-efficiency light modulation, and graphene-silicon hybrid-integrated modulators are particularly favorable due to their CMOS compatibility and low cost. The exploitation of graphene modulator latent capabilities remains an ongoing endeavour to improve the modulation and energy efficiency. Here, high-efficiency graphene-silicon hybrid-integrated thermal and electro-optical modulators are realized using gold-assisted transfer. We fabricate and demonstrate a microscale thermo-optical modulator with a tuning efficiency of 0.037 nm mW-1 and a high heating performance of 67.4 K µm3 mW-1 on a small active area of 7.54 µm2 and a graphene electro-absorption modulator featuring a high speed data rate reaching 56 Gb s-1 and a low power consumption of 200 fJ per bit. These devices show superior performance compared to the state of the art devices in terms of high efficiency, low process complexity, and compact device footage, which can support the realization of high-performance graphene-silicon hybrid-integrated photonic circuits with CMOS compatibility.

2.
Cancer Gene Ther ; 31(3): 464-471, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38177307

RESUMO

KRAS mutations occur commonly in the lung and can lead to the development of non-small cell lung cancer (NSCLC). While the mutated KRAS protein is a neoantigen, it usually does not generate an effective anti-tumor immune response on mucosal/epithelial surfaces. Despite this, mutated KRAS remains a potential target for immunotherapy since immune targeting of this protein in animal models has been effective at eliminating tumor cells. We attempted to develop a KRAS vaccine using mutated and wild-type KRAS peptides in combination with a nanoemulsion (NE) adjuvant. The efficacy of this approach was tested in an inducible mutant KRAS-mouse lung tumor model. Animals were immunized intranasally using NE with KRAS peptides. These animals had decreased CD4+FoxP3+ T cells in both lymph nodes and spleen. Immunized animals also showed higher IFN-γ and IL-17a levels to mutated KRAS that were produced by CD8+ T cells and enhancement in KRAS-specific Th1 and Th17 responses that persisted for 3 months after the last vaccination. Importantly, the immunized animals had significantly decreased tumor incidence compared to control animals. In conclusion, a mucosal approach to KRAS vaccination demonstrated the ability to induce local KRAS-specific immune responses in the lung and resulted in reduced tumor incidence.


Assuntos
Carcinoma Pulmonar de Células não Pequenas , Neoplasias Pulmonares , Camundongos , Animais , Carcinoma Pulmonar de Células não Pequenas/genética , Carcinoma Pulmonar de Células não Pequenas/terapia , Neoplasias Pulmonares/genética , Neoplasias Pulmonares/prevenção & controle , Vacinas de Subunidades Proteicas , Proteínas Proto-Oncogênicas p21(ras)/genética , Linfócitos T CD8-Positivos , Modelos Animais de Doenças , Peptídeos/genética , Mutação
3.
Clin Exp Rheumatol ; 42(2): 237-245, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38153165

RESUMO

OBJECTIVES: Anti-MDA5+ dermatomyositis was associated with poor prognosis due to the high incidence of rapid progressive interstitial lung disease, pulmonary infection. The aim of this study is to investigate the abundance and clinical relevance of exhaustion markers on peripheral CD8 T cells from patients with idiopathic inflammatory myopathy (IIM). METHODS: Twenty-nine healthy controls (HCs) and 71 patients with IIM were enrolled, including 42 with anti-MDA5+ and 18 with anti-MDA5- dermatomyositis (DM) and 11 with anti-synthetase syndrome (ASS). Flow cytometry was applied to detect PD-1, TIM-3 and LAG-3 in CD8 T cells. The clinical associations of the CD8 T cell exhaustion phenotype in patients with anti-MDA5+ DM were analysed. RESULTS: CD8 T cells from patients with anti-MDA5+ DM showed significantly increased LAG-3, TIM-3 and PD-1 compared to those from patients with anti-MDA5- IIM (18 with anti-MDA5- DM and 11 with ASS) or HCs (adjusted p all < 0.05). CD8 T cells with distinct exhaustion levels were all significantly increased in anti-MDA5+ DM patients compared with HCs (p all < 0.05). Patients with high level of PD-1+ TIM-3+LAG-3+ CD8+ T cells had a significant higher incidence of pulmonary fungal infections but lower counts of CD4+ and CD8+ T cells. ROC analysis revealed that the frequency of PD-1+TIM-3+LAG-3+CD8+ T cell significantly predicted pulmonary fungal infections (area under the curve: 0.828). CONCLUSIONS: CD8 T cells from patients with anti-MDA5+ DM show significant exhausted phenotype, and increased exhausted CD8 T cells were associated with high risk of pulmonary fungal infection.


Assuntos
Dermatomiosite , Humanos , Dermatomiosite/complicações , Receptor Celular 2 do Vírus da Hepatite A , Helicase IFIH1 Induzida por Interferon , Receptor de Morte Celular Programada 1 , Autoanticorpos , Linfócitos T CD8-Positivos , Linfócitos T , Estudos Retrospectivos , Prognóstico
4.
Clin Chim Acta ; 543: 117321, 2023 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-37019328

RESUMO

OBJECTIVE: To investigate the levels and phenotypes of peripheral natural killer (NK) cells in anti-MDA5+ dermatomyositis (DM) patients, and their association with clinical features. METHODS: Peripheral NK cell counts (NKCCs) were retrospectively collected from 497 patients with idiopathic inflammatory myopathies and 60 healthy controls. Multi-color flow cytometry was used to determine the NK cell phenotypes in additional 48 DM patients and 26 healthy controls. The association of NKCC and NK cell phenotypes with the clinical features and prognosis were analyzed in anti-MDA5+ DM patients. RESULTS: NKCC was significantly lower in anti-MDA5+ DM patients than in those with other IIM subtypes and healthy controls. A significant decrease in NKCC was associated with disease activity. Furthermore, NKCC < 27 cells/µL was an independent risk factor for 6-month mortality in anti-MDA5+ DM patients. In addition, identification of the functional phenotype of NK cells revealed significantly increased expression of the inhibitory marker CD39 in CD56brightCD16dimNK cells of anti-MDA5+ DM patients. CD39+NK cells of anti-MDA5+ DM patients showed increased expression of NKG2A, NKG2D, Ki-67, decreased expression of Tim-3, LAG-3, CD25, CD107a, and reduced TNF-α production. CONCLUSION: Decreased cell counts and inhibitory phenotype are significant characteristics of peripheral NK cells in anti-MDA5+ DM patients.


Assuntos
Dermatomiosite , Humanos , Autoanticorpos , Contagem de Células , Helicase IFIH1 Induzida por Interferon , Células Matadoras Naturais , Fenótipo , Estudos Retrospectivos
5.
PLoS One ; 17(8): e0268328, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35969523

RESUMO

Hydrosalpinx is a chronic inflammatory condition with high recurrence rate, and it is reported among female population having fallopian tubal factor infertility. Previously, we have reported that interventional ultrasound sclerotherapy improves endometrial receptivity and pregnancy rate with negligible adverse effects in patients suffering from hydrosalpinx. During present investigation, we have used next generation sequencing (NGS) to characterize the isomiR profiles from the endometrium of patients suffering from hydrosalpinx before and after interventional ultrasound sclerotherapy. Our results indicated that miRNA arm shift and switch remained unaffected when compared in patients before and after interventional ultrasound sclerotherapy. We observed that isomiRs with trimming at 3' and isomiRs with canonical sequences were lower in post-treatment than in pre-treatment group. Gene ontology (GO) annotation and KEGG pathway analysis revealed that the expression of mature mir-30 was significantly lower in the pre-treatment as compared to post treatment group while the expression of mir-30 isomiR was 4.26-fold higher in pre-treatment when compared with the post-treatment group. These different expression patterns of mir-30 mature miRNA and mir-30 isomiRs in two groups are affecting the physiological function of the endometrium. Our results suggested that differential isomiR distribution in hydrosalpinx patients before and after treatment plays an important role in hydrosalpinx incidence and can help in designing novel strategy for the treatment of hydrosalpinx in female population.


Assuntos
MicroRNAs , Salpingite , Feminino , Sequenciamento de Nucleotídeos em Larga Escala , Humanos , MicroRNAs/genética , MicroRNAs/metabolismo , Gravidez , Taxa de Gravidez , Escleroterapia/métodos , Ultrassonografia de Intervenção/métodos
6.
Microbiol Spectr ; 10(2): e0250621, 2022 04 27.
Artigo em Inglês | MEDLINE | ID: mdl-35412373

RESUMO

Wound infections with methicillin-resistant Staphylococcus aureus (MRSA) and vancomycin-resistant enterococci (VRE) are particularly difficult to treat and present a great challenge to clinicians. Nanoemulsions (NE) are novel oil-in-water emulsions formulated from soybean oil, water, solvent, and surfactants such as benzalkonium chloride (BZK). An optimal ratio of those components produces nanometer-sized particles with the positive-charged surfactant at their oil-water interface. We sought to investigate antimicrobial NE as a novel treatment to address wounds co-infected by MRSA and VRE. Swine split-thickness skin wounds were first infected with MRSA and/or VRE, then treated with the nanoemulsion formulation (X-1735) or placebo controls. Bacterial viability after treatment were determined by nutrient agar plates for total, MRSA-specific, and VRE-specific loads. In addition, inflammation indexes were scored by histopathology. When VRE infected wounds were treated with X-1735, they contained 103 lower VRE CFU counts across a 2-week period compared with placebo. Once co-infected MRSA and VRE split-thickness wounds were successfully established, topical treatment of co-infected wounds with X-1735 resulted in a reduction of bacteria by 2 to 3 logs (compared with placebo) at 3- and 14-day postinfection time points. Importantly, X-1735 was effective in significantly alleviating multilevel inflammation in the treated wounds. X-1735 is a new antimicrobial that is safe to apply to open wounds and effectively kills MRSA and VRE. It appears to also reduce inflammation in these co-infected wounds. The data suggest that this approach offers promise as an antimicrobial for open wounds with MRSA and VRE co-infection. IMPORTANCE Infections, specifically polymicrobial, can cause serious consequences when it comes to wound treatment. Prolonged treatment with antibiotics can lead to an increased risk of bacterial resistance; co-infections can complicate treatment options even further. Our research proposes a novel nanoemulsion treatment for two of the most common antibiotic resistant bacteria: methicillin-resistant Staphylococcus aureus (MRSA) and Vancomycin-resistant enterococci (VRE). This optimized topical treatment formulation not only significantly reduces inflammation and infection in MRSA or VRE infected wounds, but also in MRSA and VRE co-infected wounds as well. The work aims to provide an alternative treatment approach for multidrug-resistant organisms and decrease dependence on systemic treatments.


Assuntos
Infecções por Bactérias Gram-Positivas , Staphylococcus aureus Resistente à Meticilina , Infecções Estafilocócicas , Enterococos Resistentes à Vancomicina , Animais , Antibacterianos/farmacologia , Antibacterianos/uso terapêutico , Farmacorresistência Bacteriana Múltipla , Infecções por Bactérias Gram-Positivas/microbiologia , Inflamação , Infecções Estafilocócicas/microbiologia , Suínos , Água
7.
Drug Deliv ; 28(1): 2150-2159, 2021 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-34617850

RESUMO

We examined formulating a new antifungal agent, posaconazole (POS) and its derivatives, with different molecular vehicles. Several combinations of drug and carrier molecules were synthesized, and their antifungal activities were evaluated against Aspergillus fumigatus. Posaconazole and four of its derivatives were conjugated to either generation 5 (G5) dendrimers or partially modified G5 dendrimers. The in vitro antifungal activities of these compounds suggest that conjugates with specific chemical linkages showed better fungistatic activity than direct conjugates to POS. In particular, a polyethylene glycol (PEG)-imidazole modified G5 dendrimer demonstrated improved antifungal efficacy relative to the parent G5 molecule. Further studies were then conducted with POS derived molecules coupled to PEG-imidazole modified G5 dendrimers to achieve a highly soluble and active conjugate of POS. This conjugated macromolecule averaged 23 POS molecules per G5 and had a high solubility with 50 mg/mL, which improved the molar solubility of POS from less than 0.03 mg/mL to as high as 16 mg/mL in water. The primary release profile of the drug in human plasma was extended to over 72 h, which is reflected in the in vitro inhibition of A. fumigatus growth of over 96 h. These POS-polymer conjugates appear to be novel and efficient antifungal agents.


Assuntos
Antifúngicos/administração & dosagem , Aspergillus fumigatus/efeitos dos fármacos , Dendrímeros/química , Nanopartículas/química , Triazóis/administração & dosagem , Antifúngicos/farmacologia , Química Farmacêutica , Relação Dose-Resposta a Droga , Portadores de Fármacos/química , Liberação Controlada de Fármacos , Imidazóis/farmacologia , Polietilenoglicóis/química , Triazóis/farmacologia
8.
J Exp Clin Cancer Res ; 40(1): 118, 2021 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-33794968

RESUMO

BACKGROUND: Hepatoma is a common malignancy of the liver. The abnormal high expression of alpha-fetoprotein (AFP) is intimately associated with hepatoma progress, but the mechanism of transcriptional regulation and singularly activation of AFP gene in hepatoma is not clear. METHODS: The expression of transcription factor HBP1 and AFP and clinical significance were further analyzed in hepatoma tissues from the patients who received surgery or TACE and then monitored for relapse for up 10 years. HBP1-mediated transcriptional regulation of AFP was analyzed by Western blotting, Luciferase assay, Realtime-PCR, ChIP and EMSA. After verified the axis of HBP-AFP, its impact on hepatoma was measured by MTT, Transwell and FACS in hepatoma cells and by tumorigenesis in HBP1-/- mice. RESULTS: The relative expressions of HBP1 and AFP correlated with survival and prognosis in hepatoma patients. HBP1 repressed the expression of AFP gene by directly binding to the AFP gene promoter. Hepatitis B Virus (HBV)-encoded protein HBx promoted malignancy in hepatoma cells through binding to HBP1 directly. Icaritin, an active ingredient of Chinese herb epimedium, inhibited malignancy in hepatoma cells through enhancing HBP1 transrepression of AFP. The repression of AFP by HBP1 attenuated AFP effect on PTEN, MMP9 and caspase-3, thus inhibited proliferation and migration, and induced apoptosis in hepatoma cells. The deregulation of AFP by HBP1 contributed to hepatoma progression in mice. CONCLUSIONS: Our data clarify the mechanism of HBP1 in inhibiting the expression of AFP and its suppression in malignancy of hepatoma cells, providing a more comprehensive theoretical basis and potential solutions for the diagnosis and treatment of hepatoma.


Assuntos
Carcinoma Hepatocelular/genética , Proteínas de Grupo de Alta Mobilidade/metabolismo , Proteínas Repressoras/metabolismo , alfa-Fetoproteínas/metabolismo , Animais , Carcinoma Hepatocelular/patologia , Linhagem Celular Tumoral , Humanos , Camundongos , Transdução de Sinais , Transfecção
9.
J Nanobiotechnology ; 18(1): 135, 2020 Sep 18.
Artigo em Inglês | MEDLINE | ID: mdl-32948179

RESUMO

BACKGROUND: Targeted contrast nanoparticles for breast tumor imaging facilitates early detection and improves treatment efficacy of breast cancer. This manuscript reports the development of an epidermal growth factor receptor-2 (HER-2) specific, bi-modal, dendrimer conjugate to enhance computed tomography (CT) and magnetic resonance imaging (MRI) of HER-2-positive breast cancer. This material employs generation 5 poly(amidoamine) dendrimers, encapsulated gold nanoparticles, chelated gadolinium, and anti-human HER-2 antibody to produce the nanoparticle contrast agent. RESULTS: Testing in two mouse tumor models confirms this contrast agent's ability to image HER-2 positive tumors. Intravenous injection of this nanoparticle in mice bearing HER-2 positive mammary tumors significantly enhances MRI signal intensity by ~ 20% and improves CT resolution and contrast by two-fold. Results by flow cytometry and confocal microscopy validate the specific targeting of the conjugate and its internalization in human HER-2 positive cells. CONCLUSION: These results demonstrate that this nanoparticle conjugate can efficiently target and image HER-2 positive tumors in vivo and provide a basis for the development of this diagnostic tool for early detection, metastatic assessment and therapeutic monitoring of HER-2 positive cancers.


Assuntos
Anticorpos/farmacologia , Neoplasias da Mama/diagnóstico por imagem , Nanopartículas/química , Receptor ErbB-2/imunologia , Células A549 , Animais , Neoplasias da Mama/patologia , Sistemas de Liberação de Medicamentos , Gadolínio , Humanos , Cinética , Imageamento por Ressonância Magnética/métodos , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Camundongos Nus , Camundongos Transgênicos , Tomografia Computadorizada por Raios X/métodos
10.
ACS Appl Mater Interfaces ; 12(23): 26145-26152, 2020 Jun 10.
Artigo em Inglês | MEDLINE | ID: mdl-32410452

RESUMO

Semiconducting single-walled carbon nanotubes (SWNTs) are potential active materials for fast-growing flexible/wearable applications with low-power dissipation, especially suitable for increasingly important radio-frequency (RF) wireless biosensor systems. However, the operation frequency of the existing flexible carbon nanotube field-effect transistors (CNT-FETs) is far below the current state-of-the-art GSM spectrum frequency band (typical 850 MHz) for near-field wireless communication applications. In this paper, we successfully conduct a 900 °C annealing process for the flexible CNT-FETs and hence significantly improve their operation frequency up to 2.1 gigahertz (GHz), making it possible to cover the current GSM spectra for integrated wireless sensor systems. The high-temperature annealing process significantly improves the electrical characteristic of the flexible CNT-FETs by removing the surfactant impurities of the SWNT materials. The obtained flexible CNT-FETs exhibit record transconductance (gm) as high as 48 µS/µm. Despite an applied strain level of 2%, a characteristic frequency of over 1 GHz is observed. Further demonstration of GHz performance is also exhibited for flexible RF integrated circuits (ICs) such as frequency multipliers and mixers, which are the fundamental components for wireless applications. This work offers a new pathway for realizing SWNT-based wearable wireless GHz sensor systems with power efficiency.

11.
Vaccine ; 38(19): 3537-3544, 2020 04 23.
Artigo em Inglês | MEDLINE | ID: mdl-32245642

RESUMO

BACKGROUND: Vaccination is the most effective approach to prevent infection with highly pathogenic avian influenza (HPAI). Adjuvants are often used to induce effective immune responses and overcome the immunological weakness of recombinant HPAI antigens. Given the logistical challenges of immunization to HPAI during pandemic situations, vaccines administered via the intramuscular (I.M.) route would be of value. METHODS: A new formulation of nanoemulsion adjuvant (NE02) suitable for I.M. vaccination was developed. This NE02 was evaluated alone and in combination with CpG to develop H5 immune responses in mouse and ferret models. Measures of recombinant H5 (rH5) specific immunity evaluated included serum IgG and IgG subclasses, bronchoalveolar lavage fluid IgA, and cytokines. The activation of NF-kB was also analyzed. The efficacy of the vaccine was assessed by performing hemagglutination inhibition (HAI), virus neutralization (VN) assays, and viral challenges in ferrets. RESULTS: I.M. vaccination with rH5-NE02 significantly increased rH5-specific IgG and protected ferrets in the viral challenge model providing complete protection and sterile immunity in all animals tested. Combining NE02 and CpG produced accelerated antibody responses and this was accompanied by an elevation of IFN-γ and IL-17 responses and the downregulation of IL-5. The combination also caused a synergistic effect on NF-kB activation. In immunized ferrets after viral challenge, the rH5-NE02 + CpG vaccine via I.M. achieved at least 75% and 88% seroconversion of HAI and VN antibody responses, respectively, and improved body temperature stabilization and weight loss over NE02 alone. CONCLUSIONS: The I.M. injection of NE02 adjuvanted rH5 elicits strong and broad immune responses against H5 antigens and effectively protects animals from lethal H5 challenge. Combining this adjuvant with CpG enhanced immune responses and provided improvements in outcomes to viral challenge in ferrets. The results suggest that combinations of adjuvants may be useful to enhance H5 immune responses and improve protection against influenza infection.


Assuntos
Virus da Influenza A Subtipo H5N1 , Vírus da Influenza A , Vacinas contra Influenza , Infecções por Orthomyxoviridae , Adjuvantes Imunológicos , Animais , Anticorpos Antivirais , Furões , Camundongos , Infecções por Orthomyxoviridae/prevenção & controle
12.
Cancer Lett ; 471: 12-26, 2020 02 28.
Artigo em Inglês | MEDLINE | ID: mdl-31811908

RESUMO

Alpha-fetoprotein (AFP) is a well-established biomarker for hepatocellular carcinoma (HCC). Here, we investigated the acetylation state of AFP in vivo. AFP acetylation was regulated by the acetyltransferase CBP and the deacetylase SIRT1. Acetylation of AFP at lysines 194, 211, and 242 increased the stability of AFP protein by decreasing its ubiquitination and proteasomal degradation. AFP acetylation promoted its oncogenic role by blocking binding to the phosphatase PTEN and the pro-apoptotic protein caspase-3, which increased signaling for proliferation, migration, and invasion and decreased apoptosis. High levels of acetylated AFP in HCC tissues were associated with HBV infection and correlated with poor prognosis and decreased patient survival. In HCC cells, hepatitis B virus X protein (HBx) and palmitic acid (PA) increased the level of acetylated AFP by disrupting SIRT1-mediated deacetylation. AFP acetylation plays an important role in HCC progression and provides a new potential prognostic marker and therapeutic target for HCC.


Assuntos
Carcinoma Hepatocelular/metabolismo , Neoplasias Hepáticas/metabolismo , alfa-Fetoproteínas/metabolismo , Acetilação/efeitos dos fármacos , Sequência de Aminoácidos , Animais , Apoptose/fisiologia , Proteína de Ligação a CREB/metabolismo , Carcinoma Hepatocelular/tratamento farmacológico , Carcinoma Hepatocelular/virologia , Movimento Celular/fisiologia , Proliferação de Células/fisiologia , Células HEK293 , Células Hep G2 , Hepatite B Crônica/metabolismo , Humanos , Neoplasias Hepáticas/tratamento farmacológico , Neoplasias Hepáticas/virologia , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Nus , Invasividade Neoplásica , Ácido Palmítico/farmacologia , Prognóstico , Sirtuína 1/metabolismo , Transativadores/biossíntese , Transativadores/genética , Transativadores/metabolismo , Transfecção , Proteínas Virais Reguladoras e Acessórias/biossíntese , Proteínas Virais Reguladoras e Acessórias/genética , Proteínas Virais Reguladoras e Acessórias/metabolismo
13.
Exp Ther Med ; 18(2): 1375-1383, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31316626

RESUMO

Although the underlying mechanism of stress remains unknown, it has been associated with the pathophysiology of gastroesophageal reflux diseases, the development of which appear to be accelerated by oxidative stress and fibrosis. The aim of the current study was to investigate the effect of chronic restraint stress on esophageal oxidative stress and fibrosis, as well as the impact of oxidative stress in a murine model whereby 8-week old C57BL/6J male mice were subjected to intermittent chronic restraint stress for a two-week period. The current study demonstrated that chronic restraint stress significantly reduced the body weight of mice compared with the control group. Although chronic restraint stress did not significantly alter the levels of triglycerides or cholesterol, free fatty acid concentration was significantly increased compared with the control group. Furthermore, chronic restraint stress significantly upregulated the expression levels of several fibrotic biomarkers including collagen type I, transforming growth factor ß-1, α-smooth muscle actin and SMAD-3 compared with the control group. In addition, the expression levels of the reactive oxygen species (ROS) NADPH oxidase-4 and malondialdehyde were significantly increased, while the expression levels of nuclear factor erythroid 2-related factor 2 and heme oxygenase-1 were significantly decreased in esophageal tissue from mice in the chronic restraint stress group compared with the control group. In conclusion, chronic restraint stress may induce esophageal fibrosis by accumulating ROS and increasing fibrotic gene expression in a murine model.

14.
Oncogene ; 38(24): 4835-4855, 2019 06.
Artigo em Inglês | MEDLINE | ID: mdl-30816344

RESUMO

Genome instability is a common feature of tumor cells, and the persistent presence of genome instability is a potential mechanism of tumorigenesis. The E3 ubiquitin ligase MDM2 is intimately involved in genome instability, but its mechanisms are unclear. Our data demonstrated that the transcription factor HBP1 is a target of MDM2. MDM2 facilitates HBP1 proteasomal degradation by ubiquitinating HBP1, regardless of p53 status, thus attenuating the transcriptional inhibition of HBP1 in the expression of its target genes, such as the DNA methyltransferase DNMT1 and histone methyltransferase EZH2, which results in global DNA hypermethylation and histone hypermethylation and ultimately genome instability. The repression of HBP1 by MDM2 finally promotes cell growth and tumorigenesis. Next, we thoroughly explored the regulatory mechanism of the MDM2/HBP1 axis in DNA damage repair following ionizing radiation. Our data indicated that MDM2 overexpression-mediated repression of HBP1 delays DNA damage repair and causes cell death in a p53-independent manner. This investigation elucidated the mechanism of how MDM2 promotes genome instability and enhances tumorigenesis in the absence of p53, thus providing a theoretical and experimental basis for targeting MDM2 as a cancer therapy.


Assuntos
Instabilidade Genômica , Proteínas de Grupo de Alta Mobilidade/metabolismo , Proteínas Proto-Oncogênicas c-mdm2/fisiologia , Proteínas Repressoras/metabolismo , Ubiquitinação , Animais , Transformação Celular Neoplásica/genética , Transformação Celular Neoplásica/metabolismo , Regulação Neoplásica da Expressão Gênica , Instabilidade Genômica/genética , Células HEK293 , Células HeLa , Humanos , Células MCF-7 , Masculino , Camundongos , Camundongos Nus , Processamento de Proteína Pós-Traducional/genética , Proteínas Proto-Oncogênicas c-mdm2/metabolismo , Proteína Supressora de Tumor p53/fisiologia , Ubiquitinação/genética
15.
Vaccine ; 37(12): 1591-1600, 2019 03 14.
Artigo em Inglês | MEDLINE | ID: mdl-30795941

RESUMO

BACKGROUND: Highly pathogenic H5N1 influenza viruses remain a pandemic risk to the world population. Although vaccines are the best solution to prevent this threat, a more effective vaccine for H5 strains of influenza has yet to be developed. All existing vaccines target only serum antibody against influenza as the primary outcome, while mucosal immunity has not been addressed. To address these shortcomings we have used an effective mucosal adjuvant system to produce a prototype vaccine that provides antibody, cellular and mucosal immunity to multiple serotypes of H5. METHODS: Plant-derived recombinant H5 (rH5) antigen was mixed with a novel nanoemulsion NE01 adjuvant. The rH5-NE01 vaccine was administered intranasally to CD-1 mice and ferrets. Immunogenicity of this immunization was evaluated through rH5-specific antibody and cellular immune responses. Hemagglutination inhibition (HI) and virus neutralization (VN) assays were performed. Protection against H5N1 virus challenge was evaluated in ferrets. RESULTS: Intranasal immunization with rH5-NE01vaccine induced high titers (>106) of rH5-specific IgG in mice. In mice and ferrets this vaccine also achieved titers of ≥40 for both HI and VN. Additionally, the levels of rH5-specific IgA were significantly increased in bronchial secretions in these animals. The rH5-NE01 vaccine enhanced rH5-specific cellular immune responses including IFN-γ and IL-17. Ten-day survival post challenge was 100% in ferrets that received rH5-NE01compared to 12.5% in the PBS group. Furthermore, this vaccine prevented weight loss and increases in body temperature after H5N1 challenge as compared to the controls. Moreover, H5N1 virus in nasal wash of rH5-NE01-vaccinated ferrets was significantly decreased compared to controls. CONCLUSION: Intranasal immunization with rH5 antigen formulated with NE01 adjuvant elicited strong, broad and balanced immune responses that effectively protect against H5N1 influenza virus infection in the ferret model. The ease of formulation of rH5-NE01 makes this novel combination a promising mucosal vaccine candidate for pandemic influenza.


Assuntos
Adjuvantes Imunológicos , Emulsões , Glicoproteínas de Hemaglutininação de Vírus da Influenza/imunologia , Vírus da Influenza A/imunologia , Vacinas contra Influenza/imunologia , Infecções por Orthomyxoviridae/imunologia , Animais , Anticorpos Antivirais/sangue , Anticorpos Antivirais/imunologia , Citocinas/metabolismo , Feminino , Furões , Glicoproteínas de Hemaglutininação de Vírus da Influenza/administração & dosagem , Glicoproteínas de Hemaglutininação de Vírus da Influenza/química , Imunização , Imunogenicidade da Vacina , Imunoglobulina A/sangue , Imunoglobulina A/imunologia , Imunoglobulina G/sangue , Imunoglobulina G/imunologia , Virus da Influenza A Subtipo H5N1/imunologia , Vacinas contra Influenza/administração & dosagem , Vacinas contra Influenza/química , Masculino , Camundongos , Infecções por Orthomyxoviridae/prevenção & controle , Proteínas Recombinantes
16.
Nanoscale Res Lett ; 12(1): 393, 2017 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-28599512

RESUMO

The HfO2/TiO2/HfO2 trilayer-structure resistive random access memory (RRAM) devices have been fabricated on Pt- and TiN-coated Si substrates with Pt top electrodes by atomic layer deposition (ALD). The effect of the bottom electrodes of Pt and TiN on the resistive switching properties of trilayer-structure units has been investigated. Both Pt/HfO2/TiO2/HfO2/Pt and Pt/HfO2/TiO2/HfO2/TiN exhibit typical bipolar resistive switching behavior. The dominant conduction mechanisms in low and high resistance states (LRS and HRS) of both memory cells are Ohmic behavior and space-charge-limited current, respectively. It is found that the bottom electrodes of Pt and TiN have great influence on the electroforming polarity preference, ratio of high and low resistance, and dispersion of the operating voltages of trilayer-structure memory cells. Compared to using symmetric Pt top/bottom electrodes, the RRAM cells using asymmetric Pt top/TiN bottom electrodes show smaller negative forming voltage of -3.7 V, relatively narrow distribution of the set/reset voltages and lower ratio of high and low resistances of 102. The electrode-dependent electroforming polarity can be interpreted by considering electrodes' chemical activity with oxygen, the related reactions at anode, and the nonuniform distribution of oxygen vacancy concentration in trilayer-structure of HfO2/TiO2/HfO2 on Pt- and TiN-coated Si. Moreover, for Pt/HfO2/TiO2/HfO2/TiN devices, the TiN electrode as oxygen reservoir plays an important role in reducing forming voltage and improving uniformity of resistive switching parameters.

17.
Nanomedicine (Lond) ; 12(10): 1177-1185, 2017 May.
Artigo em Inglês | MEDLINE | ID: mdl-28447896

RESUMO

AIM: To develop NB-201, a nanoemulsion compound, as a novel microbicidal agent against methicillin-resistant Staphylococcus aureus (MRSA) infection, which is a common threat to public health but with limited therapeutic options. MATERIALS & METHODS: NB-201 was tested in in vitro and in vivo murine and porcine models infected with MRSA. RESULTS: Topical treatment of MRSA-infected wounds with NB-201 significantly decreased bacterial load and had no toxic effects on healthy skin tissues. NB-201 attenuated neutrophil sequestration in MRSA-infected wounds and inhibited epidermal and deep dermal inflammation. The levels of proinflammatory cytokines were reduced in NB-201-treated MRSA-infected wounds. CONCLUSION: NB-201 can greatly reduce inflammation characteristic of infected wounds and has antimicrobial activity that effectively kills MRSA regardless of the genetic basis of antibiotic resistance.


Assuntos
Antibacterianos/uso terapêutico , Compostos de Benzalcônio/uso terapêutico , Staphylococcus aureus Resistente à Meticilina/efeitos dos fármacos , Polissorbatos/uso terapêutico , Óleo de Soja/uso terapêutico , Infecções Estafilocócicas/tratamento farmacológico , Infecção dos Ferimentos/tratamento farmacológico , Animais , Antibacterianos/farmacologia , Compostos de Benzalcônio/farmacologia , Citocinas/análise , Combinação de Medicamentos , Feminino , Humanos , Camundongos , Testes de Sensibilidade Microbiana , Polissorbatos/farmacologia , Óleo de Soja/farmacologia , Infecções Estafilocócicas/microbiologia , Infecções Estafilocócicas/patologia , Suínos , Infecção dos Ferimentos/microbiologia , Infecção dos Ferimentos/patologia
18.
J Biol Chem ; 292(20): 8207-8222, 2017 05 19.
Artigo em Inglês | MEDLINE | ID: mdl-28348080

RESUMO

Oxidative stress can induce cell dysfunction and lead to a broad range of degenerative alterations, including carcinogenesis, aging, and other oxidative stress-related conditions. To avoid undergoing carcinogenesis in response to oxidative stress, cells trigger a succession of checkpoint responses, including premature senescence and apoptosis. Increasing evidence indicates that H2O2, an important cause of oxidative stress, functions as an important physiological regulator of intracellular signaling pathways that participate in regulation of cell premature senescence and apoptosis. However, the precise mechanisms underlying this process remain to be studied extensively. In this study, we describe the importance of Pim-1 kinase in this checkpoint response to oxidative stress. Pim-1 binds to and phosphorylates the transcription factor high mobility group box transcription factor 1 (HBP1), activating it. H2O2 enhances the interaction between Pim-1 and HBP1 and promotes HBP1 accumulation. In turn, HBP1 rapidly and selectively up-regulates Pim-1 expression in H2O2-stimulated cells, thereby creating a Pim-1-HBP1 positive feedback loop that regulates H2O2-induced premature senescence and apoptosis. Furthermore, the Pim-1-HBP1 positive feedback loop exerts its effect by regulating the senescence markers DNMT1 and p16 and the apoptosis marker Bax. The Pim-1-HBP1 axis thus constitutes a novel checkpoint pathway critical for the inhibition of tumorigenesis.


Assuntos
Apoptose/efeitos dos fármacos , Senescência Celular/efeitos dos fármacos , Regulação Enzimológica da Expressão Gênica/efeitos dos fármacos , Proteínas de Grupo de Alta Mobilidade/metabolismo , Peróxido de Hidrogênio/farmacologia , Proteínas Proto-Oncogênicas c-pim-1/biossíntese , Proteínas Repressoras/metabolismo , Regulação para Cima/efeitos dos fármacos , Apoptose/genética , Pontos de Checagem do Ciclo Celular/efeitos dos fármacos , Pontos de Checagem do Ciclo Celular/genética , Senescência Celular/genética , Inibidor p16 de Quinase Dependente de Ciclina/genética , Inibidor p16 de Quinase Dependente de Ciclina/metabolismo , DNA (Citosina-5-)-Metiltransferase 1 , DNA (Citosina-5-)-Metiltransferases/genética , DNA (Citosina-5-)-Metiltransferases/metabolismo , Células HeLa , Proteínas de Grupo de Alta Mobilidade/genética , Humanos , Estresse Oxidativo/efeitos dos fármacos , Estresse Oxidativo/genética , Proteínas Proto-Oncogênicas c-pim-1/genética , Proteínas Repressoras/genética
19.
ACS Appl Mater Interfaces ; 9(7): 6634-6643, 2017 Feb 22.
Artigo em Inglês | MEDLINE | ID: mdl-28139921

RESUMO

Al2O3- or HfO2-based nanocomposite structures with embedded CoPtx nanocrystals (NCs) on TiN-coated Si substrates have been prepared by combination of thermal atomic layer deposition (ALD) and plasma-enhanced ALD for resistive random access memory (RRAM) applications. The impact of CoPtx NCs and their average size/density on the resistive switching properties has been explored. Compared to the control sample without CoPtx NCs, ALD-derived Pt/oxide/100 cycle-CoPtx NCs/TiN/SiO2/Si exhibits a typical bipolar, reliable, and reproducible resistive switching behavior, such as sharp distribution of RRAM parameters, smaller set/reset voltages, stable resistance ratio (≥102) of OFF/ON states, better switching endurance up to 104 cycles, and longer data retention over 105 s. The possible resistive switching mechanism based on nanocomposite structures of oxide/CoPtx NCs has been proposed. The dominant conduction mechanisms in low- and high-resistance states of oxide-based device units with embedded CoPtx NCs are Ohmic behavior and space-charge-limited current, respectively. The insertion of CoPtx NCs can effectively improve the formation of conducting filaments due to the CoPtx NC-enhanced electric field intensity. Besides excellent resistive switching performances, the nanocomposite structures also simultaneously present ferromagnetic property. This work provides a flexible pathway by combining PEALD and TALD compatible with state-of-the-art Si-based technology for multifunctional electronic devices applications containing RRAM.

20.
Sci Rep ; 6: 38680, 2016 12 07.
Artigo em Inglês | MEDLINE | ID: mdl-27924851

RESUMO

The homeodomain transcription factor distal-less homeobox 3 gene (DLX3) is required for hair, tooth and skeletal development. DLX3 mutations have been found to be responsible for Tricho-Dento-Osseous (TDO) syndrome, characterized by kinky hair, thin-pitted enamel and increased bone density. Here we show that the DLX3 mutation (c.533 A>G; Q178R) attenuates osteogenic potential and senescence of bone mesenchymal stem cells (BMSCs) isolated from a TDO patient, providing a molecular explanation for abnormal increased bone density. Both DLX3 mutations (c.533 A>G and c.571_574delGGGG) delayed cellular senescence when they were introduced into pre-osteoblastic cells MC3T3-E1. Furthermore, the attenuated skeletal aging and bone loss in DLX3 (Q178R) transgenic mice not only reconfirmed that DLX3 mutation (Q178R) delayed cellular senescence, but also prevented aging-mediated bone loss. Taken together, these results indicate that DLX3 mutations act as a loss of function in senescence. The delayed senescence of BMSCs leads to increased bone formation by compensating decreased osteogenic potentials with more generations and extended functional lifespan. Our findings in the rare human genetic disease unravel a novel mechanism of DLX3 involving the senescence regulation of bone formation.


Assuntos
Anormalidades Craniofaciais/genética , Hipoplasia do Esmalte Dentário/genética , Doenças do Cabelo/genética , Proteínas de Homeodomínio/genética , Mutação , Osteogênese/genética , Fatores de Transcrição/genética , Adulto , Perda do Osso Alveolar/genética , Perda do Osso Alveolar/metabolismo , Perda do Osso Alveolar/patologia , Animais , Biomarcadores , Linhagem Celular , Senescência Celular/genética , Anormalidades Craniofaciais/metabolismo , Anormalidades Craniofaciais/patologia , Hipoplasia do Esmalte Dentário/metabolismo , Hipoplasia do Esmalte Dentário/patologia , Feminino , Expressão Gênica , Doenças do Cabelo/metabolismo , Doenças do Cabelo/patologia , Proteínas de Homeodomínio/metabolismo , Humanos , Células-Tronco Mesenquimais/metabolismo , Camundongos , Camundongos Transgênicos , Regiões Promotoras Genéticas , Ligação Proteica , Fatores de Transcrição/metabolismo
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