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1.
Acta Pharm Sin B ; 14(9): 3931-3948, 2024 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-39309509

RESUMO

Cholangiocarcinoma (CCA) is a bile duct malignancy with a dismal prognosis. This study systematically investigated the role of the ribosomal protein S6 (RPS6) gene, which is dependent in CCA. We found that RPS6 upregulation in CCA tissues was correlated with a poor prognosis. Functional investigations have shown that alterations in RPS6 expression, both gain- and loss-of function could affect the proliferation of CCA cells. In xenograft tumor models, RPS6 overexpression enhances tumorigenicity, whereas RPS6 silencing reduces it. Integration analysis using RNA-seq and proteomics elucidated downstream signaling pathways of RPS6 depletion by affecting the cell cycle, especially DNA replication. Immunoprecipitation followed by mass spectrometry has identified numerous spliceosome complex proteins associated with RPS6. Transcriptomic profiling revealed that RPS6 affects numerous alternative splicing (AS) events, and combined with RNA immunoprecipitation sequencing, revealed that minichromosome maintenance complex component 7 (MCM7) binds to RPS6, which regulates its AS and increases oncogenic activity in CCA. Targeting RPS6 with vivo phosphorodiamidate morpholino oligomer (V-PMO) significantly inhibited the growth of CCA cells, patient-derived organoids, and subcutaneous xenograft tumor. Taken together, the data demonstrate that RPS6 is an oncogenic regulator in CCA and that RPS6-V-PMO could be repositioned as a promising strategy for treating CCA.

2.
Front Genet ; 15: 1392110, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38784042

RESUMO

In this study, we investigate gynogenetic reproduction in Pengze Crucian Carp (Carassius auratus var. pengsenensis) using third-generation Nanopore sequencing to uncover structural variations (SVs) in offspring. Our objective was to understand the role of male genetic material in gynogenesis by examining the genomes of both parents and their offspring. We discovered a notable number of male-specific structural variations (MSSVs): 1,195 to 1,709 MSSVs in homologous offspring, accounting for approximately 0.52%-0.60% of their detected SVs, and 236 to 350 MSSVs in heterologous offspring, making up about 0.10%-0.13%. These results highlight the significant influence of male genetic material on the genetic composition of offspring, particularly in homologous pairs, challenging the traditional view of asexual reproduction. The gene annotation of MSSVs revealed their presence in critical gene regions, indicating potential functional impacts. Specifically, we found 5 MSSVs in the exonic regions of protein-coding genes in homologous offspring, suggesting possible direct effects on protein structure and function. Validation of an MSSV in the exonic region of the polyunsaturated fatty acid 5-lipoxygenase gene confirmed male genetic material transmission in some offspring. This study underscores the importance of further research on the genetic diversity and gynogenesis mechanisms, providing valuable insights for reproductive biology, aquaculture, and fostering innovation in biological research and aquaculture practices.

3.
Am J Pathol ; 194(7): 1346-1373, 2024 07.
Artigo em Inglês | MEDLINE | ID: mdl-38631549

RESUMO

Because the mechanotransduction by stromal stiffness stimulates the rupture and repair of the nuclear envelope in pancreatic progenitor cells, accumulated genomic aberrations are under selection in the tumor microenvironment. Analysis of cell growth, micronuclei, and phosphorylated Ser-139 residue of the histone variant H2AX (γH2AX) foci linked to mechanotransduction pressure in vivo during serial orthotopic passages of mouse KrasLSL-G12D/+;Trp53flox/flox;Pdx1-Cre (KPC) cancer cells in the tumor and in migrating through the size-restricted 3-µm micropores. To search for pancreatic cancer cell-of-origin, analysis of single-cell data sets revealed that the extracellular matrix shaped an alternate route of acinar-ductal transdifferentiation of acinar cells into topoisomerase II α (TOP2A)-overexpressing cancer cells and derived subclusters with copy number amplifications in MYC-PTK2 (protein tyrosine kinase 2) locus and PIK3CA. High-PTK2 expression is associated with 171 differentially methylated CpG loci, 319 differentially expressed genes, and poor overall survival in The Cancer Genome Atlas-Pancreatic Adenocarcinoma cohort. Abolished RGD-integrin signaling by disintegrin KG blocked the PTK2 phosphorylation, increased cancer apoptosis, decreased vav guanine nucleotide exchange factor 1 (VAV1) expression, and prolonged overall survival in the KPC mice. Reduction of α-smooth muscle actin deposition in the CD248 knockout KPC mice remodeled the tissue stroma and down-regulated TOP2A expression in the epithelium. In summary, stromal stiffness induced the onset of cancer cells-of-origin by ectopic TOP2A expression, and the genomic amplification of MYC-PTK2 locus via alternative transdifferentiation of pancreatic progenitor cells is the vulnerability useful for disintegrin KG treatment.


Assuntos
Instabilidade Cromossômica , Progressão da Doença , Neoplasias Pancreáticas , Animais , Neoplasias Pancreáticas/patologia , Neoplasias Pancreáticas/genética , Neoplasias Pancreáticas/metabolismo , Camundongos , Humanos , Carcinoma in Situ/patologia , Carcinoma in Situ/genética , Carcinoma in Situ/metabolismo , Células Estromais/metabolismo , Células Estromais/patologia , Microambiente Tumoral , Mecanotransdução Celular , Quinase 1 de Adesão Focal
4.
Biosensors (Basel) ; 13(12)2023 Dec 13.
Artigo em Inglês | MEDLINE | ID: mdl-38131787

RESUMO

Enrofloxacin, a fluoroquinolone widely used in animal husbandry, presents environmental and human health hazards due to its stability and incomplete hydrolysis leading to residue accumulation. To address this concern, a highly sensitive aptamer biosensor utilizing a localized surface plasmon resonance (LSPR) sensing chip and microfluidic technology was developed for rapid enrofloxacin residue detection. AuNPs were prepared by the seed method and the AuNPs-Apt complexes were immobilized on the chip by the sulfhydryl groups modified on the end of the aptamer. The properties and morphologies of the sensing chip and AuNPs-Apt complexes were characterized by Fourier transform infrared spectroscopy (FTIR), UV-Vis spectrophotometer, and scanning electron microscope (SEM), respectively. The sensing chip was able to detect enrofloxacin in the range of 0.01-100 ng/mL with good linearity, and the relationship between the response of the sensing chip and the concentration was Δλ (nm) = 1.288log ConENR (ng/mL) + 5.245 (R2 = 0.99), with the limit of detection being 0.001 ng/mL. The anti-interference, repeatability, and selectivity of this sensing chip were studied in detail. Compared with other sensors, this novel aptamer biosensor based on AuNPs-Apt complexes is expected to achieve simple, stable, and economical application in the field of enrofloxacin detection.


Assuntos
Técnicas Biossensoriais , Nanopartículas Metálicas , Animais , Humanos , Ressonância de Plasmônio de Superfície/métodos , Enrofloxacina , Ouro/química , Limite de Detecção , Nanopartículas Metálicas/química , Técnicas Biossensoriais/métodos , Oligonucleotídeos
5.
Biosens Bioelectron ; 237: 115537, 2023 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-37467534

RESUMO

A surface plasmon resonance (SPR) optical fiber sensor with multimode-coreless-multimode (MNM) structure was developed, which modified by L-glutamine-binding protein (QBP) for detection of L-glutamine (Gln). The QBP was immobilized on the surface of gold films by chemical cross-linking and exhibited a binding affinity for L-glutamine. The conformation of QBP can be changed from the "open" to the "closed", which led to a red-shift of the SPR peak when QBP bounded to L-glutamine. There was a good linear correlation between is a dependence of the SPR peak on and the concentration of L-glutamine concentration in the range 10-100 µM, with a sensitivity of 10.797nm/log10[Gln] for L-glutamine in the in vitro embryo culture (IVC) medium environment, and the limit of detection (LOD) is 1.187 µM. This QBP-modified MNM structure optical fiber SPR sensor provides a new idea for the developmental potential assessment of embryos in the process of in vitro embryo culture.


Assuntos
Técnicas Biossensoriais , Ressonância de Plasmônio de Superfície , Fibras Ópticas , Glutamina , Tecnologia de Fibra Óptica
6.
J Pharmacol Exp Ther ; 382(3): 346-355, 2022 09.
Artigo em Inglês | MEDLINE | ID: mdl-35840338

RESUMO

The benefit of once-weekly basal insulin is less frequent dosing, which has the potential to reduce the barrier to injection therapy and impact patient activation, adherence and compliance, quality of life, and outcomes. Basal Insulin Fc (BIF, LY3209590, or insulin efsitora alfa) is a once-weekly basal insulin in clinical testing for type 1 and type 2 diabetes mellitus. BIF is comprised of a novel single-chain variant of insulin fused to a human IgG2 fragment crystallizable region of an antibody domain using a peptide linker. The in vitro binding affinity of BIF for the human insulin receptor (IR) was two orders of magnitude weaker relative to human insulin. BIF stimulated IR phosphorylation in cells with reduced potency, yet full agonism, and exhibited a significantly faster dephosphorylation kinetic profile than human insulin or AspB10 insulin. BIF stimulated de novo lipogenesis in 3T3-L1 adipocytes and cell proliferation in SAOS-2 and H4IIE cells with ≥70-fold reduction in in vitro potency compared with human insulin. BIF possessed markedly reduced binding to hIGF-1R, making definitive measurements unattainable. In vivo pharmacology studies using streptozotocin-treated diabetic rats demonstrated a significant decrease in blood glucose compared with vehicle-treated animals 24 hours post-injection, persisting through 336 hours following subcutaneous administration. In streptozotocin-treated rats, BIF reached time at maximum concentration at 48 hours and possessed a clearance rate of ∼0.85 ml/h per kg, with a terminal half-life of ∼120 hours following subcutaneous administration. These results demonstrate BIF has an in vitro pharmacological profile similar to native insulin, with significantly reduced potency and an extended time-action profile in vivo that supports once-weekly dosing in humans. SIGNIFICANCE STATEMENT: BIF is a novel basal insulin Fc-fusion protein designed for once-weekly dosing. In this study, we demonstrate that BIF has an in vitro pharmacological profile similar to human insulin, but with weaker potency across assays for IR binding and activity. BIF has a PD and PK profile in STZ-treated rats supportive of weekly dosing in humans.


Assuntos
Diabetes Mellitus Experimental , Diabetes Mellitus Tipo 2 , Animais , Diabetes Mellitus Experimental/metabolismo , Diabetes Mellitus Tipo 2/tratamento farmacológico , Humanos , Insulina/metabolismo , Qualidade de Vida , Ratos , Estreptozocina
7.
Oncogene ; 41(22): 3162-3176, 2022 05.
Artigo em Inglês | MEDLINE | ID: mdl-35501460

RESUMO

Posttranscriptional modifications in RNA have been considered to contribute to disease pathogenesis and tumor progression. NOL1/NOP2/Sun domain family member 2 (NSUN2) is an RNA methyltransferase that promotes tumor progression in several cancers. Pancreatic cancer relapse inevitably occurs even in cases where primary tumors have been successfully treated. Associations of cancer progression due to reprogramming of the cancer methyl-metabolome and the cancer genome have been noted, but the effect of base modifications, namely 5-methylcytosine (m5C), in the transcriptome remains unclear. Aberrant regulation of 5-methylcytosine turnover in cancer may affect posttranscriptional modifications in coding and noncoding RNAs in disease pathogenesis. Mutations in NSUN2 have been reported as drivers of neurodevelopmental disorders in mice, and upregulated expression of NSUN2 in tumors of the breast, bladder, and pancreas has been reported. In this study, we conducted mRNA whole transcriptomic bisulfite sequencing to categorize NSUN2 target sites in the mRNA of human pancreatic cancer cells. We identified a total of 2829 frequent m5C sites in mRNA from pancreatic cancer cells. A total of 90.9% (2572/2829) of these m5C sites were mapped to annotated genes in autosomes and sex chromosomes X and Y. Immunohistochemistry staining confirmed that the NSUN2 expression was significantly upregulated in cancer lesions in the LSL-KrasG12D/+;Trp53fl/fl;Pdx1-Cre (KPC) spontaneous pancreatic cancer mouse model induced by Pdx1-driven Cre/lox system expressing mutant KrasG12D and p53 deletion. The in vitro phenotypic analysis of NSUN2 knockdown showed mild effects on pancreatic cancer cell 2D/3D growth, morphology and gemcitabine sensitivity in the early phase of tumorigenesis, but cumulative changes after multiple cell doubling passages over time were required for these mutations to accumulate. Syngeneic transplantation of NSUN2-knockdown KPC cells via subcutaneous injection showed decreased stromal fibrosis and restored differentiation of ductal epithelium in vivo. SIGNIFICANCE: Transcriptome-wide mRNA bisulfite sequencing identified candidate m5C sites of mRNAs in human pancreatic cancer cells. NSUN2-mediated m5C mRNA metabolism was observed in a mouse model of pancreatic cancer. NSUN2 regulates cancer progression and epithelial differentiation via mRNA methylation.


Assuntos
Carcinoma Ductal Pancreático , Neoplasias Pancreáticas , 5-Metilcitosina , Animais , Carcinoma Ductal Pancreático/genética , Carcinoma Ductal Pancreático/patologia , Transformação Celular Neoplásica/genética , Modelos Animais de Doenças , Humanos , Metiltransferases/metabolismo , Camundongos , Neoplasias Pancreáticas/genética , Neoplasias Pancreáticas/patologia , Proteínas Proto-Oncogênicas p21(ras)/metabolismo , RNA , RNA Mensageiro/genética , Sulfitos , Neoplasias Pancreáticas
8.
Proc Natl Acad Sci U S A ; 119(13): e2116506119, 2022 03 29.
Artigo em Inglês | MEDLINE | ID: mdl-35333651

RESUMO

SignificanceTirzepatide is a dual agonist of the glucose-dependent insulinotropic polypeptide receptor (GIPR) and the glucagon-like peptide-1 receptor (GLP-1R), which are incretin receptors that regulate carbohydrate metabolism. This investigational agent has proven superior to selective GLP-1R agonists in clinical trials in subjects with type 2 diabetes mellitus. Intriguingly, although tirzepatide closely resembles native GIP in how it activates the GIPR, it differs markedly from GLP-1 in its activation of the GLP-1R, resulting in less agonist-induced receptor desensitization. We report how cryogenic electron microscopy and molecular dynamics simulations inform the structural basis for the unique pharmacology of tirzepatide. These studies reveal the extent to which fatty acid modification, combined with amino acid sequence, determines the mode of action of a multireceptor agonist.


Assuntos
Diabetes Mellitus Tipo 2 , Receptores dos Hormônios Gastrointestinais , Diabetes Mellitus Tipo 2/tratamento farmacológico , Diabetes Mellitus Tipo 2/metabolismo , Polipeptídeo Inibidor Gástrico/metabolismo , Polipeptídeo Inibidor Gástrico/farmacologia , Polipeptídeo Inibidor Gástrico/uso terapêutico , Receptor do Peptídeo Semelhante ao Glucagon 1/metabolismo , Humanos , Incretinas/farmacologia , Receptores dos Hormônios Gastrointestinais/agonistas , Receptores dos Hormônios Gastrointestinais/metabolismo , Receptores dos Hormônios Gastrointestinais/uso terapêutico
9.
FEBS J ; 289(9): 2657-2671, 2022 05.
Artigo em Inglês | MEDLINE | ID: mdl-34826178

RESUMO

Insulin receptor (IR) phosphorylation is critical for the assessment of the extent of IR agonism and nuances in the downstream signaling cascade. A thorough identification and monitoring of the phosphorylation events is important for understanding the process of insulin signaling transduction and regulation. Although IR phosphorylation has been studied extensively in the past decades, only a handful of phosphorylation sites can be identified by either traditional antibody-based assays or recent large-scale mass spectrometry-based phosphoproteomics approaches. In the present study, the most exhaustive assessment of the IR phosphorylation was conducted using nano-liquid chromatography-tandem mass spectrometry, in which 13 IR phosphorylation sites and 22 combinations thereof were analyzed. The kinetic analysis included Y965, Y972, S968/969, and S974/976 in the juxtamembrane region; Y1158, Y1162, and Y1163 in the kinase domain; and Y1328, Y1334, S1278, S1320, S1321, and T1348 in the C-terminal region. Employing two different receptor agonists (i.e. insulin and an IR peptide agonist), the data revealed contrasting phosphorylation kinetics across these sites with dynamics far more diverse than expected for known IR agonists. Notably, cell trafficking experiments revealed that the IR peptide agonist was incapable of inducing IR to the early endosome, which is probably linked to a difference in IR phosphorylation. The present study provides a powerful tool for investigating IR signaling and trafficking that will benefit the design of IR agonists with improved therapeutic utility.


Assuntos
Insulina , Receptor de Insulina , Insulina/metabolismo , Cinética , Espectrometria de Massas , Fosforilação , Receptor de Insulina/metabolismo
10.
J Clin Invest ; 131(12)2021 06 15.
Artigo em Inglês | MEDLINE | ID: mdl-34003802

RESUMO

Tirzepatide (LY3298176), a dual GIP and GLP-1 receptor (GLP-1R) agonist, delivered superior glycemic control and weight loss compared with GLP-1R agonism in patients with type 2 diabetes. However, the mechanism by which tirzepatide improves efficacy and how GIP receptor (GIPR) agonism contributes is not fully understood. Here, we show that tirzepatide is an effective insulin sensitizer, improving insulin sensitivity in obese mice to a greater extent than GLP-1R agonism. To determine whether GIPR agonism contributes, we compared the effect of tirzepatide in obese WT and Glp-1r-null mice. In the absence of GLP-1R-induced weight loss, tirzepatide improved insulin sensitivity by enhancing glucose disposal in white adipose tissue (WAT). In support of this, a long-acting GIPR agonist (LAGIPRA) was found to enhance insulin sensitivity by augmenting glucose disposal in WAT. Interestingly, the effect of tirzepatide and LAGIPRA on insulin sensitivity was associated with reduced branched-chain amino acids (BCAAs) and ketoacids in the circulation. Insulin sensitization was associated with upregulation of genes associated with the catabolism of glucose, lipid, and BCAAs in brown adipose tissue. Together, our studies show that tirzepatide improved insulin sensitivity in a weight-dependent and -independent manner. These results highlight how GIPR agonism contributes to the therapeutic profile of dual-receptor agonism, offering mechanistic insights into the clinical efficacy of tirzepatide.


Assuntos
Tecido Adiposo Branco/metabolismo , Polipeptídeo Inibidor Gástrico/farmacologia , Receptor do Peptídeo Semelhante ao Glucagon 1/agonistas , Resistência à Insulina , Obesidade/metabolismo , Tecido Adiposo Branco/patologia , Aminoácidos de Cadeia Ramificada/genética , Aminoácidos de Cadeia Ramificada/metabolismo , Animais , Peso Corporal/efeitos dos fármacos , Peso Corporal/genética , Receptor do Peptídeo Semelhante ao Glucagon 1/genética , Receptor do Peptídeo Semelhante ao Glucagon 1/metabolismo , Camundongos , Camundongos Knockout , Obesidade/tratamento farmacológico , Obesidade/genética , Obesidade/patologia
11.
Sensors (Basel) ; 21(3)2021 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-33535428

RESUMO

A new optical fiber sensor based on the fluorescence lifetime was prepared for specific detection of sulfate ion concentration, where 1,1'-(anthracene-9,10-diylbis(methylene))bis(3-(dodecylcarbamoyl)pyridin-1-ium) acted as the sulfate fluorescent probe. The probe was immobilized in a porous cellulose acetate membrane to form the sensitive membrane by the immersion precipitation method, and polyethylene glycol 400 acted as a porogen. The sensing principle was proven, as a sulfate ion could form a complex with the probe through a hydrogen bond, which led to structural changes and fluorescence for the probe. The signals of the fluorescence lifetime data were collected by the lock-in amplifier and converted into the phase delay to realize the detection of sulfate ions. Based on the phase-modulated fluorometry, the relationship between the phase delay of the probe and the sulfate ion concentration was described in the range from 2 to 10 mM. The specificity and response time of this optical fiber sensor were also researched.

12.
Clin Epigenetics ; 12(1): 87, 2020 06 17.
Artigo em Inglês | MEDLINE | ID: mdl-32552862

RESUMO

BACKGROUND: Cancer subtype switching, which involves unclear cancer cell origin, cell fate decision, and transdifferentiation of cells within a confined tumor microenvironment, remains a major problem in pancreatic cancer (PDA). RESULTS: By analyzing PDA subtypes in The Cancer Genome Atlas, we identified that epigenetic silencing of apoptosis-associated tyrosine kinase (AATK) inversely was correlated with mRNA expression and was enriched in the quasi-mesenchymal cancer subtype. By comparing early mouse pancreatic lesions, the non-invasive regions showed AATK co-expression in cells with acinar-to-ductal metaplasia, nuclear VAV1 localization, and cell cycle suppression; but the invasive lesions conversely revealed diminished AATK expression in those with poorly differentiated histology, cytosolic VAV1 localization, and co-expression of p63 and HNF1α. Transiently activated AATK initiates acinar differentiation into a ductal cell fate to establish apical-basal polarization in acinar-to-ductal metaplasia. Silenced AATK and ectopically expressed p63 and HNF1α allow the proliferation of ductal PanINs in mice. CONCLUSION: Epigenetic silencing of AATK regulates the cellular transdifferentiation, proliferation, and cell cycle progression in converting PDA-subtypes.


Assuntos
Proteínas Reguladoras de Apoptose/genética , Epigênese Genética/genética , Metaplasia/genética , Neoplasias Pancreáticas/genética , Proteínas Tirosina Quinases/genética , Idoso , Animais , Diferenciação Celular , Metilação de DNA/genética , Modelos Animais de Doenças , Feminino , Inativação Gênica , Fator 1-alfa Nuclear de Hepatócito/genética , Humanos , Metaplasia/diagnóstico , Camundongos , Pessoa de Meia-Idade , Neoplasias Pancreáticas/patologia , Gravidez , Proteínas Proto-Oncogênicas c-vav/genética , RNA Mensageiro/genética , Transativadores/genética , Microambiente Tumoral/genética
13.
Nanotechnology ; 31(9): 095501, 2020 Feb 21.
Artigo em Inglês | MEDLINE | ID: mdl-31703221

RESUMO

For the early diagnosis of gastric cancer, microRNA-148a (miRNA-148a) as a promising biomarker is measured by a simple colorimetric biosensor due to its unique surface plasmon resonance (SPR) absorption of gold nanoparticles (AuNPs). In the assay system, the sensing probes are facilitated by the conjugation of AuNPs with RNA probes (RNAP) via Au-S bonds, which align in a tail-to-tail fashion onto the target RNA. When miRNA-148a is introduced, a sandwich hybridization reaction is triggered between the AuNP-RNAP conjugates and targets, resulting in changes in the SPR absorption band, microscopic distribution and macroscopic color of the AuNP solution. Following this principle, this colorimetric method is able to quantitatively detect miRNA-148a at nanomolar level with a limit of ∼1.9 nM, and exhibits high sensitivity and selectivity by a low-cost UV-vis spectrometer or even the naked eye. Moreover, the AuNP network materials with a characteristic sharp 'melting transition' provide significant guidance for the reusability of DNA or RNA biosensors.


Assuntos
Técnicas Biossensoriais/métodos , Nanopartículas Metálicas/química , MicroRNAs/análise , Sondas RNA/química , Neoplasias Gástricas/diagnóstico , Técnicas Biossensoriais/instrumentação , Colorimetria , Ouro/química , Humanos , Ressonância de Plasmônio de Superfície
14.
Mater Sci Eng C Mater Biol Appl ; 107: 110329, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31761178

RESUMO

A label-free glucose biosensor is constructed successfully based on the long period fiber grating (LPFG) functionalized with graphene oxide (GO)-glucose oxidase (GOD) via the chemical crosslink method. GO coated on the surface of LPFG can immobilize GOD by the plentiful binding sites because of its favorable combination of exceptionally high surface-to-volume ratio. The structure and characterization of GOD-GO-modified LPFG are studied by the optical microscope, Fourier transformation infrared spectrometer (FTIR), Raman spectroscopy, scanning electron microscope (SEM) and atomic force microscopy (AFM), respectively. The reaction between GOD and glucose create gluconic acid and H2O2, which will lead to an evident shift of LPFG transmission spectrum due to the greater change of the surrounding refractive index (SRI). The GOD-GO-modified LPFG sensor shows a linear response with a response coefficient of 0.77 nm/(mg/mL). This biosensor has good selectivity and can be used for the detection of practical sample. The GOD-GO-modified LPFG biosensor has great prospect in the pharmaceutical research and medical diagnosis fields.


Assuntos
Técnicas Biossensoriais/instrumentação , Técnicas Biossensoriais/métodos , Glucose/análise , Grafite/química , Enzimas Imobilizadas/química , Enzimas Imobilizadas/metabolismo , Desenho de Equipamento , Gluconatos/química , Glucose/química , Glucose Oxidase/química , Glucose Oxidase/metabolismo , Peróxido de Hidrogênio/química , Concentração de Íons de Hidrogênio , Microscopia de Força Atômica , Microscopia Eletrônica de Varredura , Fibras Ópticas , Refratometria , Espectroscopia de Infravermelho com Transformada de Fourier , Análise Espectral Raman , Fatores de Tempo
15.
ACS Appl Mater Interfaces ; 11(43): 40868-40874, 2019 Oct 30.
Artigo em Inglês | MEDLINE | ID: mdl-31593428

RESUMO

An ultrasensitive nitric oxide (NO) gas sensor based on the graphene oxide (GO)-coated long-period fiber grating (LPFG) was constructed successfully because of its excellent sensitivity to the surrounding refractive index (SRI) change. The surface morphology and structure of GO coated on LPFG were characterized by the scanning electron microscope (SEM), scanning probe microscope (SPM), and Raman spectroscopy, respectively. The adsorption principle of NO molecules by GO was calculated in detail by density functional theory (DFT) and further characterized by Fourier transform infrared spectrometry (FT-TR) and X-ray photoelectron spectroscopy (XPS). Our studies demonstrate that the adsorption principle of NO molecules by GO was the combined effect of physical adsorption and chemical adsorption because of the formation of C-N bonds between GO and NO and the oxidization of NO to NO2. The NO sensor exhibits excellent sensing performance in the NO concentration range of 0 to 400 ppm.

16.
Biosens Bioelectron ; 146: 111760, 2019 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-31605987

RESUMO

A novel optical fiber glucose biosensor based on fluorescent carbon quantum dots (CQDs)-glucose oxidase (GOD)/cellulose acetate (CA) complex sensitive film was fabricated, in which the dip-coating method was adopted to immobilize the CQDs-GOD/CA complex sensitive film onto the end face of the optical fiber. The surface morphology, microstructure and optical performances of the sensitive film were characterized by field emission scanning electron microscope (FESEM), atomic force microscope (AFM), Zeiss Axiovert 25 inverted microscope, Fourier transform infrared spectroscopy (FTIR), Ultraviolet-visible spectrophotometer and fluorescence spectrophotometer, respectively. The developed fiber-optic biosensor exhibits high sensitivity and repeatability for continuous online detection of low concentration glucose, allowing visualization of real-time glucose fluctuations over a period of time. The change ratios in fluorescence intensity of the biosensor are linear with glucose concentration in various ranges including micromole and nanomole levels, and the relationship between relative fluorescence intensity ratio and glucose concentration complies well with the modified Stern-Volmer equation in the range of 10-200 µmol/L with the detection limit of 6.43 µM, and in the range of 10-100 nmol/L with the detection limit of 25.79 nM, respectively.


Assuntos
Técnicas Biossensoriais/instrumentação , Glicemia/análise , Celulose/análogos & derivados , Glucose Oxidase/química , Fibras Ópticas , Carbono/química , Celulose/química , Desenho de Equipamento , Tecnologia de Fibra Óptica/instrumentação , Fluorescência , Humanos , Limite de Detecção , Pontos Quânticos/química
17.
Chemosphere ; 236: 124385, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31545192

RESUMO

Heavy metal pollution may affect plant growth. The focus of this study was to explore remediation agents that alleviate cadmium toxicity in plants. The Citrus maxima (grapefruit) seedlings were cultivated for 10 days under hydroponic conditions amended with different concentrations of Cd2+ (50 and 200 mg/L) and CDs (600 and 900 mg/L). Our observations on roots and leaves showed that, the plant exposed to 200 mg/L Cd2+ alone was damaged, supported by the changes in anthocyanin contents, activity of antioxidant enzymes and cell membrane peroxidation damage (up to 35.8-45%). However, the physiological properties of the plant were improved upon exposed to 200 mg/L Cd2+ plus 900 mg/L CDs; it can be ascribed to Cd2+ sorption to the co-exposed CDs which reduced its freely dissolved concentration by more than 22.5%, thus significantly reducing the amount of Cd2+ entered the plant roots by 50.7-89.4%. Due to the oxidative stress induced by Cd2+ exposure at 200 mg/L, expression of glutathione-producing genes was up-regulated by 30-360% relative to the control, while the genes expression upon exposure to 200 mg/L Cd2+ and 900 mg/L CDs was reduced by 48.4-91.5% relative to that exposed to 200 mg/L Cd2+ alone. However, detoxification of CDs on plant leaves at 600 mg/L was insignificant, because a portion of Cd2+ taken up by roots can be transported to leaves associated with the internalized CDs. Therefore, CDs can be utilized as a repair agent to mitigate toxicity of Cd2+ to plant especially at a high amendment level (900 mg/L).


Assuntos
Cádmio/toxicidade , Citrus/efeitos dos fármacos , Pontos Quânticos/química , Adsorção , Antioxidantes/metabolismo , Cádmio/química , Cádmio/metabolismo , Carbono/química , Carbono/metabolismo , Citrus/crescimento & desenvolvimento , Citrus/metabolismo , Produção Agrícola , Glutationa/metabolismo , Estresse Oxidativo/efeitos dos fármacos , Folhas de Planta/efeitos dos fármacos , Folhas de Planta/crescimento & desenvolvimento , Folhas de Planta/metabolismo , Raízes de Plantas/efeitos dos fármacos , Raízes de Plantas/crescimento & desenvolvimento , Raízes de Plantas/metabolismo , Pontos Quânticos/metabolismo , Plântula/efeitos dos fármacos , Plântula/crescimento & desenvolvimento , Plântula/metabolismo
18.
ACS Appl Mater Interfaces ; 11(37): 33941-33945, 2019 Sep 18.
Artigo em Inglês | MEDLINE | ID: mdl-31454218

RESUMO

Most of the renewable and sustainable natural energy is distributed uneven on the earth in time and space. Here we proposed a new kind of thermoelectric generator, which can use the temperature difference caused by passive cooling via the atmospheric window. This generator can continuously output electric energy anywhere 24 h a day independent of the existence of any natural or manmade energy resource. A test generator with two couples of n-p thermoelectric legs has been prepared. The created average temperature difference is 4.4 K and average voltage is 1.78 mV in a whole day. This design paves a path to the pollution-free and sustainable power generation which is not restricted by time and space and not consuming any existing energy resource.

19.
Artigo em Inglês | MEDLINE | ID: mdl-31228712

RESUMO

Ovaries (O) are specialized tissues that play critical roles in producing oocytes and hormones. The crustacean hepatopancreas (H) is a metabolic organ that plays important functions including absorption, storage of nutrients and vitellogenesis during growth and ovarian development. However, genetic information on the biological functions of the crustacean ovaries and hepatopancreas are limited. This study compared the transcriptome in the ovary and the hepatopancreas of female P. trituberculatus fed two different diets containing 0% (SL0) and 4% soybean lecithin (SL4), respectively during the growth and ovarian maturation stages by Illumina HiSeq4000 sequencer. The differences between ovary and hepatopancreas of P. trituberculatus were also compared at transcriptional level. A total of 55,667 unigenes were obtained with mean length of 962 bps across the four treatment groups (SL0_O, SL4_O, SL0_H and SL4_H). In ovary, there were 257 differentially expressed genes (DEGs) between SL0_O and SL4_O, with 145 down- and 112 up-regulated genes in the SL4_O group. Candidate genes involved in ovarian development were detected in SL4_H group. In hepatopancreas, 146 DEGs were found between SL0_H and SL4_H, including 43 down- and 103 up-regulated genes in the SL4_H group. The specific DEGs were mainly involved with lipid related metabolism pathways, including fat digestion and absorption, PPAR signaling pathway and insulin resistance. 14,725 DEGs were found in the comparison between SL0_O and SL4_H, including 7250 up- and 7475 down-regulated genes in the SL4_H group. The specific DEGs were mainly involved with lipid (fat digestion and absorption, linoleic acid metabolism), hormone (steroid hormone biosynthesis, ovarian steroidogenesis, etc), and amino acid (phenylalanine metabolism, arginine biosynthesis, tyrosine) related metabolism pathways. Crabs fed the SL4 diet exhibited higher gene expression of cryptocyanin 1 (cc1), cryptocyanin 2 (cc2) and neuroparsin 1 (np1) in hepatopancreas and ovarian than those fed the SL0 diet, however, crab fed SL4 diet showed higher gene expression of fatty acid-binding protein 1 (fabp1), vitellogenin (vtg) and Delta-6 desaturase-like protein (fadsd6) in hepatopancreas than those fed the SL0 diet. Moreover, crabs fed the SL0 diet had lower gene expression of vtg, extracellular copper­zinc superoxide dismutase (cuznsod) and estrogen sulfotransferase (ests) in ovary compared to those fed the diet containing 4% soybean lecithin. These results might provide important clues with respect to elucidating the molecular mechanisms underlying the regulation of phospholipid on the gonadal development and lipid metabolism of P. trituberculatus.


Assuntos
Braquiúros/genética , Dieta , Glycine max/química , Hepatopâncreas/metabolismo , Lecitinas/administração & dosagem , Ovário/metabolismo , Transcriptoma , Animais , Feminino , Metabolismo dos Lipídeos
20.
Cancer Lett ; 456: 13-22, 2019 08 01.
Artigo em Inglês | MEDLINE | ID: mdl-31051214

RESUMO

Relative to several other p21-activated kinase (PAK) family members, the role of PAK3 in regulating cancer cell functions remains unclear. Our study obtained evidence that PAK3 regulates the Akt-GSK3ß-ß-catenin signaling by acting as Ser473-Akt kinase in several pancreatic cancer cell lines. Specifically, knockdown of PAK3 or overexpression of dominant-negative PAK3 inhibited the phosphorylation of Ser473-Akt and GSK3ß, resulting in the proteasomal degradation of ß-catenin. Conversely, overexpression of PAK3 led to activation of Akt signaling and increased ß-catenin expression. These changes, however, were not noted with the silencing and/or overexpression of PAK1, PAK2, or PAK4, which underlies the impetus of PAK3 as a key effector in governing malignant phenotypes in these pancreatic cancer cells, including cancer stem cell (CSC) expansion. Accordingly, PAK3 depletion effectively suppresses tumorsphere formation, ALDH activity, and the expression of CSC surface markers. Moreover, we used a stable knockdown clone of AsPC-1 cells to demonstrate the in vivo efficacy of PAK3 inhibition in suppressing tumorigenesis and xenograft tumor growth. Together, these findings suggest the potential role of PAK3 as a target for pancreatic cancer therapy, which warrants further investigations.


Assuntos
Proliferação de Células , Glicogênio Sintase Quinase 3 beta/metabolismo , Células-Tronco Neoplásicas/enzimologia , Neoplasias Pancreáticas/enzimologia , Proteínas Proto-Oncogênicas c-akt/metabolismo , beta Catenina/metabolismo , Quinases Ativadas por p21/metabolismo , Animais , Linhagem Celular Tumoral , Feminino , Regulação Enzimológica da Expressão Gênica , Regulação Neoplásica da Expressão Gênica , Humanos , Camundongos Nus , Células-Tronco Neoplásicas/patologia , Neoplasias Pancreáticas/genética , Neoplasias Pancreáticas/patologia , Fosforilação , Serina , Transdução de Sinais , Esferoides Celulares , Carga Tumoral , beta Catenina/genética , Quinases Ativadas por p21/genética
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