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1.
Front Endocrinol (Lausanne) ; 14: 1292596, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-38149100

RESUMO

It has been well documented that there is a two-way relationship between diabetes mellitus and periodontitis. Diabetes mellitus represents an established risk factor for chronic periodontitis. Conversely, chronic periodontitis adversely modulates serum glucose levels in diabetic patients. Activated immune and inflammatory responses are noted during diabetes and periodontitis, under the modulation of similar biological mediators. These activated responses result in increased activity of certain immune-inflammatory mediators including adipokines and microRNAs in diabetic patients with periodontal disease. Notably, certain microbes in the oral cavity were identified to be involved in the occurrence of diabetes and periodontitis. In other words, these immune-inflammatory mediators and microbes may potentially serve as biomarkers for risk assessment and therapy selection in diabetes and periodontitis. In this review, we briefly provide an updated overview on different potential biomarkers, providing novel diagnostic and therapeutic insights on periodontal complications and diabetes mellitus.


Assuntos
Periodontite Crônica , Diabetes Mellitus Tipo 2 , Humanos , Periodontite Crônica/complicações , Periodontite Crônica/diagnóstico , Fatores de Risco , Biomarcadores , Mediadores da Inflamação
2.
Front Endocrinol (Lausanne) ; 14: 1179050, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37600707

RESUMO

Introduction: Female breast cancer has risen to be the most common malignancy worldwide, causing a huge disease burden for both patients and society. Both senescence and oxidative stress attach importance to cancer development and progression. However, the prognostic roles of senescence and oxidative stress remain obscure in breast cancer. In this present study, we attempted to establish a predictive model based on senescence-oxidative stress co-relation genes (SOSCRGs) and evaluate its clinical utility in multiple dimensions. Methods: SOSCRGs were identified via correlation analysis. Transcriptome data and clinical information of patients with breast invasive carcinoma (BRCA) were accessed from The Cancer Genome Atlas (TCGA) and GSE96058. SVM algorithm was employed to process subtype classification of patients with BRCA based on SOSCRGs. LASSO regression analysis was utilized to establish the predictive model based on SOSCRGs. Analyses of the predictive model with regards to efficacy evaluation, subgroup analysis, clinical association, immune infiltration, functional strength, mutation feature, and drug sensitivity were organized. Single-cell analysis was applied to decipher the expression pattern of key SOSCRGs in the tumor microenvironment. Additionally, qPCR was conducted to check the expression levels of key SOSCRGs in five different breast cancer cell lines. Results: A total of 246 SOSCRGs were identified. Two breast cancer subtypes were determined based on SOSCRGs and subtype 1 showed an active immune landscape. A SOSCRGs-based predictive model was subsequently developed and the risk score was clarified as independent prognostic predictors in breast cancer. A novel nomogram was constructed and exhibited favorable predictive capability. We further ascertained that the infiltration levels of immune cells and expressions of immune checkpoints were significantly influenced by the risk score. The two risk groups were characterized by distinct functional strengths. Sugar metabolism and glycolysis were significantly upregulated in the high risk group. The low risk group was deciphered to harbor PIK3CA mutation-driven tumorigenesis, while TP53 mutation was dominant in the high risk group. The analysis further revealed a significantly positive correlation between risk score and TMB. Patients in the low risk group may also sensitively respond to several drug agents. Single-cell analysis dissected that ERRFI1, ETS1, NDRG1, and ZMAT3 were expressed in the tumor microenvironment. Moreover, the expression levels of the seven SOSCRGs in five different breast cancer cell lines were quantified and compared by qPCR respectively. Conclusion: Multidimensional evaluations verified the clinical utility of the SOSCRGs-based predictive model to predict prognosis, aid clinical decision, and risk stratification for patients with breast cancer.


Assuntos
Neoplasias da Mama , Feminino , Humanos , Neoplasias da Mama/tratamento farmacológico , Neoplasias da Mama/genética , Genes Reguladores , Prognóstico , Nomogramas , Carcinogênese , Microambiente Tumoral/genética
3.
Int J Lab Hematol ; 45(6): 961-968, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-37605839

RESUMO

INTRODUCTION: Mutations in the hemoglobin subunit delta (HBD) gene (MIM#142000) are associated with decreased levels of the Hemoglobin A2 (Hb A2 ) fraction. We aimed to examine the prevalence of HBD gene mutations and summarize their characteristics in the Chinese population. METHODS: Individuals who exhibited Hb A2 levels below 1.8%, with or without Hb A2 variant peaks, were chosen for further investigation. Hemoglobin analysis was conducted using capillary electrophoresis. Common α and ß-thalassemia in China were detected using gap-PCR and reverse dot blot hybridization. The presence of HBD gene mutations was confirmed by DNA sequencing. RESULTS: A total of 188 patients were identified as carriers of the HBD gene mutation, with a prevalence of approximately 0.46%. We discovered 36 types of mutations, 30 of which resulted in δ-globin variants, while the remaining 6 resulted in δ-thalassemia. The most common mutation was HBD:c.-127 T > C, accounting for 87.2% of δ-thalassemia cases. In addition, we identified 11 novel HBD gene mutations and found 10 cases compounded with other common thalassemias. CONCLUSION: We observed a high prevalence of HBD gene mutations in southern China. Our findings provide a genetic basis for screening for δ-thalassemia and enrich the spectrum of HBD gene mutations.


Assuntos
Hemoglobinas Anormais , Talassemia beta , Talassemia delta , Humanos , Talassemia beta/epidemiologia , Talassemia beta/genética , Talassemia beta/diagnóstico , Talassemia delta/diagnóstico , Talassemia delta/epidemiologia , Talassemia delta/genética , População do Leste Asiático , Hemoglobina A2/genética , Hemoglobinas Anormais/genética , Mutação
4.
Hum Immunol ; 84(9): 464-470, 2023 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-37394297

RESUMO

BACKGROUND: CKD is a major cause of morbidity and mortality worldwide. Considerable evidence now indicates that renal inflammation plays a central role in the initiation and progression of CKD. Recent investigations have demonstrated that IFNλ plays an important role in the pathogenesis of autoimmune and inflammatory diseases. However, the association of IFNλ with CKD is still poorly understood. OBJECTIVE: To analyze the correlation between IFNλ levels and pro-inflammatory cytokines, and to investigate the effect of IFNλ on PBMCs in patients with CKD. METHODS: PBMCs were harvested from patients with CKD and healthy controls for measuring the expression level of inflammatory cytokines by RT-qPCR. Spearman correlation test was used to analyze correlation between IFNλ and cytokines as well as eGFR. PBMCs from healthy individuals and CKD patients were subjected to IFNλ protein stimulation. IL6, TNFα, IL10, ISG15 and MX1 mRNA level were measured by RT-PCR, STAT1 and phosphorylated STAT1 protein level were measured by Western blot. RESULTS: Patients with CKD showed higher levels of IFNλ in PBMCs compared to healthy controls. IFNλ mRNA levels were associated with cytokines and eGFR. The transcription of IL6, TNFα, and IL10 was significantly increased in healthy human PBMCs after IFNλ stimulation. In addition, IFNλ acts on PBMCs by p-STAT1 and ISG15 as well as MX1. CONCLUSION: High expression of IFNλ was found in CKD patients and was associated with eGFR and disease-related cytokines. More importantly, IFNλ promoted the expression of pro-inflammatory cytokines in PBMCs, suggesting a potential pro-inflammatory role of IFNλ in CKD.


Assuntos
Insuficiência Renal Crônica , Fator de Necrose Tumoral alfa , Humanos , Fator de Necrose Tumoral alfa/metabolismo , Interferon lambda , Interleucina-10/metabolismo , Interleucina-6/metabolismo , Citocinas/metabolismo , Insuficiência Renal Crônica/metabolismo , RNA Mensageiro/genética , Leucócitos Mononucleares/metabolismo
5.
Ann Transl Med ; 8(6): 310, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-32355754

RESUMO

BACKGROUND: Disruption of ß-cell insulin secretion and viability caused by excessive ethanol consumption increases type 2 diabetes mellitus (T2DM) pathogenesis risk. Fibroblast growth factor 21 (FGF21) plays a significant role in regulating lipid and glucose homeostasis. Recently, FGF21, best known for its role in lipid and glucose homeostasis regulation, and its obligate co-receptor ß-klotho have been shown to inhibit ethanol ingestion and metabolism. It remains unclear whether heavy ethanol intake modulates islet FGF21 expression and function. This study investigated the relationship between ethanol exposure, FGF21, and islet function in vivo/ex vivo islet and in vitro cell models. METHODS: Mice were gavaged with 3.5 g/kg ethanol or saline for 1-3 weeks (long-term exposure). Human MIN6 cells and isolated islets were cultured and treated with 80 mM ethanol for 24 h (short-term exposure) to mimic excessive ethanol consumption. We applied the oral glucose tolerance test (OGTT), blood glucometry, enzyme-linked immunosorbent assay (ELISAs) for insulin and FGF21, glucose stimulated insulin secretion (GSIS) testing, reverse-transcription (RT)-polymerase chain reaction (PCR), and western blot experiments. RESULTS: Long-term ethanol treatment induced FGF21 resistance in mouse pancreatic islets. Moreover, ethanol exposure damaged insulin secretory ability and glucose homeostasis. In vitro and ex vivo experiments showed that short-term ethanol treatment upregulated the expression of FGF21 signaling pathway-related genes and proteins, without affecting ß-cell survival or function. CONCLUSIONS: Long-term ethanol consumption induces FGF21 resistance-mediated pancreatic ß-cell dysfunction, and thus diabetes pathogenesis risk.

6.
Microb Pathog ; 145: 104231, 2020 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-32344179

RESUMO

Mycoplasma genitalium is one of the sexually transmitted pathogens that cause significant morbidity in the host. The development of effective therapeutic procedures is urgently needed to counter the multi-drug resistant events imposed by this pathogen. In the current version of M. genitalium G37 genome, 512 open reading frames have been identified. The function of 91 proteins encoded by M. genitalium genes was found to be hypothetical and these proteins were termed hypothetical proteins (HPs). This study aims to carry out functional characterization of HPs by a systems biology approach. Functional assignments of 61 HPs were made with high confidence. They belong to different functional groups, such as DNA-binding proteins, helicases and transporters. Approximately 26% of HPs were identified as transporters, suggesting that M. genitalium is likely to rely on the exogenous nutrient supply for survival. A group of 20 proteins was predicted to be virulence factors, indicating the pathogenic characteristics of M. genitalium. Among the coding proteins, six proteins were pathogen-specific and could serve as potential drug targets by subtractive proteomics analysis. Network analysis of the HPs suggested that several critical proteins were involved in SOS response and stringent response in M. genitalium. These findings provided a better picture of M. genitalium genome and novel clues for studying the potential infection mechanism in this bacterium.


Assuntos
Infecções por Mycoplasma , Mycoplasma genitalium , Preparações Farmacêuticas , Humanos , Mycoplasma genitalium/genética , Fases de Leitura Aberta , Proteômica , Biologia de Sistemas
7.
Stem Cells ; 37(11): 1416-1428, 2019 11.
Artigo em Inglês | MEDLINE | ID: mdl-31400234

RESUMO

Induction of ß-cell regeneration from endogenous cells represents a highly promising strategy in stem cell-based treatment for patients with diabetes. Recently, calorie restriction has been shown to affect the regulation of tissue and cell regeneration, including ß cells, via metabolic related mechanisms. Here, we examined the potential utility of sirtuin 1 (SIRT1), a calorie restriction mimetic, for stimulating ß-cell regeneration and the underlying mechanisms of such stimulation. The present results showed that SIRT1 activation with SRT1720 promoted ß-cell regeneration in streptozotocin (STZ)-induced ß-cell-deficient neonatal rats. This beneficial effect involved enhanced activation of neurogenin3 (NGN3)-positive endocrine progenitors from pancreatic ductal cells, rather than an expansion of residual ß cells. A dynamic expression profile of SIRT1 was observed in endocrine progenitors both during ß-cell regeneration in neonatal rats and in the second transition phase of mouse pancreas development. Consistently, SRT1720 treatment upregulated endocrine progenitor differentiation in cultured pancreatic rudiments. Upregulation of NGN3 by SIRT1 activation was through stimulating AMP-activated protein kinase (AMPK) signaling-mediated fatty acid oxidation (FAO) in human pancreatic progenitor cells; AMPK inhibition abolished these effects. The present findings demonstrate a promotional effect of SIRT1 activation on ß-cell restoration and endocrine progenitor differentiation that involves regulation of AMPK signaling-mediated FAO. Stem Cells 2019;37:1416-1428.


Assuntos
Proteínas Quinases Ativadas por AMP/metabolismo , Ácidos Graxos/metabolismo , Sirtuína 1/metabolismo , Células-Tronco/metabolismo , Trifosfato de Adenosina/metabolismo , Animais , Animais Recém-Nascidos , Glicemia/metabolismo , Western Blotting , Células Cultivadas , Feminino , Humanos , Hiperglicemia/induzido quimicamente , Insulina/sangue , Células Secretoras de Insulina/metabolismo , Lentivirus/genética , Metabolismo dos Lipídeos/genética , Metabolismo dos Lipídeos/fisiologia , Oxirredução , Pâncreas/metabolismo , Ratos , Ratos Wistar , Transdução de Sinais/genética , Transdução de Sinais/fisiologia , Sirtuína 1/genética , Estreptozocina/toxicidade
8.
Int J Mol Sci ; 20(17)2019 Aug 21.
Artigo em Inglês | MEDLINE | ID: mdl-31438545

RESUMO

Pancreatic progenitor cells (PPCs) are the primary source for all pancreatic cells, including beta-cells, and thus the proliferation and differentiation of PPCs into islet-like cell clusters (ICCs) opens an avenue to providing transplantable islets for diabetic patients. Meanwhile, mesenchymal stem cells (MSCs) can enhance the development and function of different cell types of interest, but their role on PPCs remains unknown. We aimed to explore the mechanism-of-action whereby MSCs induce the in vitro and in vivo PPC/ICC development by means of our established co-culture system of human PPCs with human fetal bone marrow-derived MSCs. We examined the effect of MSC-conditioned medium on PPC proliferation and survival. Meanwhile, we studied the effect of MSC co-culture enhanced PPC/ICC function in vitro and in vivo co-/transplantation. Furthermore, we identified IGF1 as a critical factor responsible for the MSC effects on PPC differentiation and proliferation via IGF1-PI3K/Akt and IGF1-MEK/ERK1/2, respectively. In conclusion, our data indicate that MSCs stimulated the differentiation and proliferation of human PPCs via IGF1 signaling, and more importantly, promoted the in vivo engraftment function of ICCs. Taken together, our protocol may provide a mechanism-driven basis for the proliferation and differentiation of PPCs into clinically transplantable islets.


Assuntos
Diferenciação Celular/fisiologia , Proliferação de Células/fisiologia , Células-Tronco Mesenquimais/metabolismo , Células-Tronco Mesenquimais/fisiologia , Pâncreas/citologia , Células-Tronco/citologia , Células-Tronco/fisiologia , Apoptose/fisiologia , Células Cultivadas , Técnicas de Cocultura , Humanos , Células-Tronco Mesenquimais/citologia , Fosfatidilinositol 3-Quinases/metabolismo , Células-Tronco/metabolismo
9.
Zhongguo Zhong Yao Za Zhi ; 43(22): 4427-4432, 2018 Nov.
Artigo em Chinês | MEDLINE | ID: mdl-30593234

RESUMO

To minimize the predatory harvest of Heterosmilax yunnanensis and maintain the sustainable utilization of its resources, a study on the tending technology of wild H. yunnanensis was carried out. The results showed that the tuber tending model had a higher seed emergence rate, shorter growth period and easier control of male and female ratios than other tending models; by removing shrubs, topping, bending pruning, controlling insects and pests and other effective technical measures, the growth period of H. yunnanensis was shortened; the average annual net income of the tending area was 1 086 yuan/mu (1 mu≈666.67 m²), which was 86.9% higher than before. This study was conducive to increasing the yield and quality of H. yunnanensis in Karst landform area, and instructive for the tending of other wild traditional Chinese medicinal herbs in this area.


Assuntos
Smilacaceae , Feminino , Humanos , Masculino
10.
Mol Plant Microbe Interact ; 31(2): 224-232, 2018 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-29173048

RESUMO

We explored the genetic basis of the promiscuous symbiosis of Sophora flavescens with diverse rhizobia. To determine the impact of Nod factors (NFs) on the symbiosis of S. flavescens, nodulation-related gene mutants of representative rhizobial strains were generated. Strains with mutations in common nodulation genes (nodC, nodM, and nodE) failed to nodulate S. flavescens, indicating that the promiscuous nodulation of this plant is strictly dependent on the basic NF structure. Mutations of the NF decoration genes nodH, nodS, nodZ, and noeI did not affect the nodulation of S. flavescens, but these mutations affected the nitrogen-fixation efficiency of nodules. Wild-type Bradyrhizobium diazoefficiens USDA110 cannot nodulate S. flavescens, but we obtained 14 Tn5 mutants of B. diazoefficiens that nodulated S. flavescens. This suggested that the mutations had disrupted a negative regulator that prevents nodulation of S. flavescens, leading to nonspecific nodulation. For Ensifer fredii CCBAU 45436 mutants, the minimal NF structure was sufficient for nodulation of soybean and S. flavescens. In summary, the mechanism of promiscuous symbiosis of S. flavescens with rhizobia might be related to its nonspecific recognition of NF structures, and the host specificity of rhizobia may also be controlled by currently unknown nodulation-related genes.


Assuntos
Rhizobiaceae/fisiologia , Sophora/fisiologia , Simbiose/fisiologia , Mutação , Nodulação/genética , Nodulação/fisiologia , Sophora/genética , Sophora/microbiologia
11.
SLAS Technol ; 22(1): 36-43, 2017 02.
Artigo em Inglês | MEDLINE | ID: mdl-27139694

RESUMO

Collective cell migration plays important roles in many physiological processes such as embryonic development, tissue repair, and angiogenesis. A "wound" occurs when epithelial cells are lost and/or damaged due to some external factors, and collective cell migration takes place in the following wound-healing process. To study this cellular behavior, various kinds of wound-healing assays are developed. In these assays, a "wound," or a "cell-free region," is created in a cell monolayer mechanically, chemically, optically, or electrically. These assays are useful tools in studying the effects of certain physical or chemical stimuli on the wound-healing process. Most of these methods have disadvantages such as creating wounds of different sizes or shapes, yielding batch-to-batch variation, and damaging the coating of the cell culture surface. In this study, we used ultraviolet (UV) lights to selectively kill cells and create a wound out of a cell monolayer. A comparison between the current assay and the traditional scratch assay was made, indicating that these two methods resulted in similar wound-healing rates. The advantages of this UV-created wound-healing assay include fast and easy procedure, high throughput, and no direct contact to cells.


Assuntos
Movimento Celular , Técnicas Citológicas/métodos , Células Epiteliais/fisiologia , Células Epiteliais/efeitos da radiação , Raios Ultravioleta , Cicatrização , Animais , Camundongos , Modelos Biológicos , Células NIH 3T3
12.
Clin Sci (Lond) ; 131(3): 247-260, 2017 02 01.
Artigo em Inglês | MEDLINE | ID: mdl-27980130

RESUMO

G-protein-coupled receptor 120 (GPR120) is a putative target for obesity and diabetes therapies. However, it remains controversial whether resident GPR120 plays a direct regulatory role in islet ß-cell insulin secretion. The present study examined this issue in isolated rodent islets and rat ß-cell line INS-1E, and assessed the role of GPR120 in islet insulin secretion in obese non-diabetic (OND) and diabetic states. GPR120 expression was detected in rodent islet ß-cells. Docosahexaenoic acid (DHA) and synthetic GPR120 agonist GSK137647 (GSK) augmented insulin release from rat/mouse islets and INS-1E; DHA effects were partially mediated by GPR40. GPR120 knockdown and overexpression attenuated and enhanced DHA effects in INS-1E respectively. DHA and GSK improved postprandial hyperglycaemia of diabetic mice. Inhibition of calcium signalling in INS-1E reduced GPR120 activation-induced insulinotropic effects. The insulinotropic effects of DHA/GSK were amplified in OND rat islets, but diminished in diabetic rat islets. GPR120 and peroxisome proliferator-activated receptor γ (PPARγ) expression were elevated in OND islets and palmitic acid (PA)-treated INS-1E, but reduced in diabetic islets and high glucose-treated INS-1E. PPARγ activation increased GPR120 expression in rat islets and INS-1E. DHA and GSK induced protein kinase B (Akt)/extracellular signal-regulated kinase (ERK) phosphorylation in rodent islets and INS-1E, and these effects were altered in OND and diabetic states. Taken together, the present study indicates that (i) GPR120 activation has an insulinotropic influence on ß-cells with the involvement of calcium signalling; (ii) GPR120 expression in ß-cells and GPR120-mediated insulinotropic effects are altered in OND and diabetic states in distinct ways, and these alterations may be mediated by PPARγ.


Assuntos
Diabetes Mellitus Experimental/metabolismo , Células Secretoras de Insulina/metabolismo , Insulina/metabolismo , Obesidade/metabolismo , Receptores Acoplados a Proteínas G/metabolismo , Compostos de Anilina/farmacologia , Animais , Apoptose , Sinalização do Cálcio , Linhagem Celular , Ácidos Docosa-Hexaenoicos , Técnicas de Silenciamento de Genes , Teste de Tolerância a Glucose , Secreção de Insulina , Sistema de Sinalização das MAP Quinases , Masculino , Camundongos Endogâmicos C57BL , PPAR gama/metabolismo , Proteínas Proto-Oncogênicas c-akt/metabolismo , Ratos Wistar , Ratos Zucker , Receptores Acoplados a Proteínas G/agonistas , Receptores Acoplados a Proteínas G/antagonistas & inibidores , Receptores Acoplados a Proteínas G/genética , Sulfonamidas/farmacologia
13.
J Vis Exp ; (114)2016 08 13.
Artigo em Inglês | MEDLINE | ID: mdl-27584698

RESUMO

Microfluidic devices are capable of creating a precise and controllable cellular micro-environment of pH, temperature, salt concentration, and other physical or chemical stimuli. They have been commonly used for in vitro cell studies by providing in vivo like surroundings. Especially, how cells response to chemical gradients, electrical fields, and shear stresses has drawn many interests since these phenomena are important in understanding cellular properties and functions. These microfluidic chips can be made of glass substrates, silicon wafers, polydimethylsiloxane (PDMS) polymers, polymethylmethacrylate (PMMA) substrates, or polyethyleneterephthalate (PET) substrates. Out of these materials, PMMA substrates are cheap and can be easily processed using laser ablation and writing. Although a few microfluidic devices have been designed and fabricated for generating multiple, coexisting chemical and electrical stimuli, none of them was considered efficient enough in reducing experimental repeats, particular for screening purposes. In this report, we describe our design and fabrication of two PMMA-based microfluidic chips for investigating cellular responses, in the production of reactive oxygen species and the migration, under single or coexisting chemical/electrical/shear stress stimuli. The first chip generates five relative concentrations of 0, 1/8, 1/2, 7/8, and 1 in the culture regions, together with a shear stress gradient produced inside each of these areas. The second chip generates the same relative concentrations, but with five different electric field strengths created within each culture area. These devices not only provide cells with a precise, controllable micro-environment but also greatly increase the experimental throughput.


Assuntos
Dispositivos Lab-On-A-Chip , Técnicas Analíticas Microfluídicas , Eletricidade , Humanos , Microfluídica , Estresse Mecânico
14.
Antioxid Redox Signal ; 24(8): 419-33, 2016 Mar 10.
Artigo em Inglês | MEDLINE | ID: mdl-26464216

RESUMO

AIMS: Reactive oxygen species (ROS) act as second messengers for redox modification of transcription factors essential for differentiation. The nicotinamide adenine dinucleotide phosphate (NADPH) oxidase, a major source of ROS, has been shown to regulate differentiation of various progenitor cells, while its role in pancreatic endocrine cell differentiation is unclear. This study was aimed at this knowledge gap. RESULTS: Our results showed that ROS levels were dynamically changed during pancreas development concomitant with endocrine cell differentiation induced by modest exogenous ROS in rudiment cultures. NOX4, but not NOX2, the member of NADPH oxidase, was expressed persistently in endocrine lineage and showed high activity in critical pancreas development phase. Inhibition of NADPH oxidase activity impeded the differentiation of endocrine progenitors in vitro, and exogenous ROS reversed this effect. Studies performed in streptozotocin (STZ)-injected neonatal rats showed that diphenyleneiodonium (DPI) obstructed ß-cell regeneration through the suppression of neurogenin 3 (NGN3) expression, but not Ki67-labeling ß-cells, indicating that ROS stimulation promoted differentiation beyond proliferation of ß-cells. Inhibition of NADPH oxidase also reduced expression of SRY (sex-determining region Y)-box 9 (SOX9), a transcriptional regulator of Ngn3, in endocrine precursor cells, both in vivo and in vitro. Overexpression of SOX9 attenuated the reduction of NGN3 induced by suppression of NADPH oxidase. INNOVATION AND CONCLUSION: This is the first study to demonstrate NADPH oxidase, especially NOX4-dependent ROS that promotes pancreatic progenitor cell differentiation into endocrine cells both in vitro and in vivo, probably through the regulation of SOX9. We provide evidence that NADPH oxidase-dependent ROS-mediated signaling is necessary for endocrine cell differentiation, which provides a potential strategy for efficient generation of insulin-producing cells in clinical application.


Assuntos
Células Secretoras de Insulina/citologia , NADPH Oxidases/metabolismo , Oniocompostos/farmacologia , Espécies Reativas de Oxigênio/metabolismo , Estreptozocina/administração & dosagem , Animais , Animais Recém-Nascidos , Diferenciação Celular/efeitos dos fármacos , Células Cultivadas , Regulação da Expressão Gênica/efeitos dos fármacos , Células Secretoras de Insulina/metabolismo , Masculino , Camundongos , Pâncreas/citologia , Pâncreas/crescimento & desenvolvimento , Transdução de Sinais
15.
Biomicrofluidics ; 9(5): 054120, 2015 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-26487906

RESUMO

Cell migration is an essential process involved in the development and maintenance of multicellular organisms. Electric fields (EFs) are one of the many physical and chemical factors known to affect cell migration, a phenomenon termed electrotaxis or galvanotaxis. In this paper, a microfluidics chip was developed to study the migration of cells under different electrical and chemical stimuli. This chip is capable of providing four different strengths of EFs in combination with two different chemicals via one simple set of agar salt bridges and Ag/AgCl electrodes. NIH 3T3 fibroblasts were seeded inside this chip to study their migration and reactive oxygen species (ROS) production in response to different EF strengths and the presence of ß-lapachone. We found that both the EF and ß-lapachone level increased the cell migration rate and the production of ROS in an EF-strength-dependent manner. A strong linear correlation between the cell migration rate and the amount of intracellular ROS suggests that ROS are an intermediate product by which EF and ß-lapachone enhance cell migration. Moreover, an anti-oxidant, α-tocopherol, was found to quench the production of ROS, resulting in a decrease in the migration rate.

16.
Opt Lett ; 40(6): 966-9, 2015 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-25768158

RESUMO

Stabilization of the relative carrier-envelope (CE) phase for hybridly synchronized two-color fs Yb and Er fiber-laser systems is demonstrated for the first time by utilizing the feed-forward scheme based on an acousto-optic frequency shifter. The slow drift issues arising from the feed-forward scheme are solved by adding the in-loop relative CE frequency coarse stabilization via modulating the laser pump current. Sub-fs timing locking between the two-color pulses is still maintained due to the fast response and large locking range of hybrid synchronization. The approach provides an alternative way to obtain phase-stable synchronized two-color pulses with higher pulse energies.

17.
Opt Lett ; 38(17): 3456-9, 2013 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-23988983

RESUMO

We report experimental as well as theoretical investigation of the key factors that influence the relative timing jitter between hybrid synchronized ultrafast Yb and Er fiber laser systems. Experimental results show that, within the achievable synchronization range, the synchronization performance varies significantly with the relative injection timing between the 1 µm master and 1.5 µm slave pulses. This observation is in agreement with the insights obtained from the theoretical analysis, which identifies the retiming effect as a function of the initial condition of the master-slave pulse collision. By controlling the relative injection timing with a low-bandwidth intracavity feedback, relative timing jitter as low as 0.87 fs (within 1.9 MHz bandwidth) is successfully obtained.

18.
Mol Phylogenet Evol ; 57(2): 528-35, 2010 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-20692352

RESUMO

Previous phylogenetic studies based on DNA sequence data have partially resolved taxonomic relationships among Pestalotiopsis species. There are still some morphological characters whose phylogenetic significance have not been assessed properly due to limited taxon sampling, in particular the degree of pigmentation of median cells. In this study, the stability of pigmentation of median cells of conidia in Pestalotiopsis species was evaluated in subculture, and a molecular phylogenetic analysis was conducted on 45 strains belonging to 26 species in order to reappraise the pigmentation of median cells for its significance in the taxonomy of Pestalotiopsis. Phylogenetic relationships were inferred from nucleotide sequences in ITS regions (ITS1, 5.8S and ITS2) and ß-tubulin 2 gene (tub2). The results showed that pigmentation of median cells was stable and it could be a key character in the taxonomy of Pestalotiopsis species. Instead of "concolorous" and "versicolor" proposed by Steyeart (1949), "brown to olivaceous" and "umber to fuliginous" are described and proposed in this paper.


Assuntos
DNA Fúngico/genética , Filogenia , Pigmentação/genética , Análise de Sequência de DNA , Xylariales/classificação , Xylariales/genética , Sequência de Bases , Dados de Sequência Molecular , Reação em Cadeia da Polimerase , Homologia de Sequência de Aminoácidos
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