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1.
Ann Surg ; 2024 Jun 03.
Artigo em Inglês | MEDLINE | ID: mdl-38829115

RESUMO

Radiation therapy is a clinically proven, localized preventive measure for heterotopic ossification (HO). Despite its efficacy, there is a lack of standardization of radiation prescription dosing and fractionation, and the mechanism of the impact of radiation in HO prevention remains unknown. Here, using an established mouse model of traumatic HO induced by burn and tenotomy, we demonstrate that 7Gy in one fraction delivered to the injury site within 72 hours postoperatively significantly decreases HO formation and improves hindlimb range of motion. In-depth single-cell transcriptomic analyses, in combination with immunofluorescent staining, demonstrate decreased cellular numbers as well as aberrant endochondral differentiation and downregulation of associated upstream signaling pathways in irradiated mesenchymal progenitor cells. Our study provides the framework for future mechanistic and clinically relevant studies exploring radiation efficacy in preventing HO formation.

2.
Nucleic Acids Res ; 50(8): 4484-4499, 2022 05 06.
Artigo em Inglês | MEDLINE | ID: mdl-35438787

RESUMO

Vibrio cholerae biofilm formation/maintenance is controlled by myriad factors; chief among these are the regulator VpsR and cyclic di-guanosine monophosphate (c-di-GMP). VpsR has strong sequence similarity to enhancer binding proteins (EBPs) that activate RNA polymerase containing sigma factor σ54. However, we have previously shown that transcription from promoters within the biofilm biogenesis/maintenance pathways uses VpsR, c-di-GMP and RNA polymerase containing the primary sigma factor (σ70). Previous work suggested that phosphorylation of VpsR at a highly conserved aspartate, which is phosphorylated in other EBPs, might also contribute to activation. Using the biofilm biogenesis promoter PvpsL, we show that in the presence of c-di-GMP, either wild type or the phospho-mimic VpsR D59E activates PvpsL transcription, while the phospho-defective D59A variant does not. Furthermore, when c-di-GMP levels are low, acetyl phosphate (Ac∼P) is required for significant VpsR activity in vivo and in vitro. Although these findings argue that VpsR phosphorylation is needed for activation, we show that VpsR is not phosphorylated or acetylated by Ac∼P and either sodium phosphate or potassium phosphate, which are not phosphate donors, fully substitutes for Ac∼P. We conclude that VpsR is an unusual regulator that senses phosphate directly, rather than through phosphorylation, to aid in the decision to form/maintain biofilm.


Assuntos
Vibrio cholerae , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Biofilmes , GMP Cíclico/análogos & derivados , GMP Cíclico/metabolismo , Proteínas de Ligação a DNA/genética , RNA Polimerases Dirigidas por DNA/genética , RNA Polimerases Dirigidas por DNA/metabolismo , Regulação Bacteriana da Expressão Gênica , Fosfatos/metabolismo , Fator sigma/genética , Fator sigma/metabolismo , Vibrio cholerae/metabolismo
3.
BMC Musculoskelet Disord ; 25(1): 28, 2024 Jan 02.
Artigo em Inglês | MEDLINE | ID: mdl-38166999

RESUMO

BACKGROUND: The optimal timing for reimplantation for periprosthetic joint infection (PJI) has not been established and varies from a few weeks to several months. The aim of this study was to assess the commendable time between implant removal and reimplantation in patients who underwent two-stage exchange arthroplasty for PJI. METHODS: We retrospectively reviewed 361 patients who were treated with two-stage exchange arthroplasty for hip and knee chronic PJI at our institution between January 2000 and December 2018. Patient characteristics, comorbidities, surgical variables, microbiology data, and time to reimplantation were recorded. All patients were followed for a minimum of one year. Treatment failure was defined by Delphi criteria. Logistic regression analyses were used to calculate survival rates and adjusted odds ratios (ORs) of treatment failure. RESULTS: In final analysis, 27 (7.5%) had treatment failure. Factors related to treatment failure including interim spacer exchange (OR, 3.13; confidence interval (CI), 1.04-9.09, p = 0.036), higher ESR level at reimplantation (OR, 1.85; CI, 1.05-3.57; p = 0.04), and time to reimplantation (OR, 1.00; CI, 1.003-1.005, p = 0.04). Performing revision arthroplasty surgery from 16 to 20 weeks had highest successful rate. The reimplantation over 24 weeks had a lower successful rate. However, no statistical significance in comparing each interval group. CONCLUSION: Our study emphasized the importance of timely reimplantation in achieving successful outcomes. Factors such as ESR levels, spacer exchange, and the duration of time to reimplantation influenced the likelihood of treatment failure in two-stage exchange arthroplasty for hip and knee PJI.


Assuntos
Artrite Infecciosa , Artroplastia de Quadril , Artroplastia do Joelho , Infecções Relacionadas à Prótese , Humanos , Artroplastia de Quadril/efeitos adversos , Artroplastia do Joelho/efeitos adversos , Resultado do Tratamento , Infecções Relacionadas à Prótese/diagnóstico , Infecções Relacionadas à Prótese/cirurgia , Infecções Relacionadas à Prótese/etiologia , Estudos Retrospectivos , Estudos de Coortes , Fatores de Tempo , Reoperação/efeitos adversos , Reimplante , Artrite Infecciosa/cirurgia
4.
Zhongguo Dang Dai Er Ke Za Zhi ; 26(4): 337-342, 2024 Apr 15.
Artigo em Zh | MEDLINE | ID: mdl-38660896

RESUMO

OBJECTIVES: To investigate the effects of different angles of pulmonary surfactant (PS) administration on the incidence of bronchopulmonary dysplasia and intracranial hemorrhage in preterm infants. METHODS: A prospective study was conducted on 146 preterm infants (gestational age <32 weeks) admitted to the Department of Neonatology, Provincial Hospital Affiliated to Anhui Medical University from January 2019 to May 2023. The infants were randomly assigned to different angles for injection of pulmonary surfactant groups: 0° group (34 cases), 30° group (36 cases), 45° group (38 cases), and 60° group (38 cases). Clinical indicators and outcomes were compared among the groups. RESULTS: The oxygenation index was lower in the 60° group compared with the other three groups, with shorter invasive ventilation time and oxygen use time, and a lower incidence of bronchopulmonary dysplasia than the other three groups (P<0.05). The incidence of intracranial hemorrhage was lower in the 60° group compared to the 0° group (P<0.05). The cure rate in the 60° group was higher than that in the 0° group and the 30° group (P<0.05). CONCLUSIONS: The clinical efficacy of injection of pulmonary surfactant at a 60° angle is higher than other angles, reducing the incidence of intracranial hemorrhage and bronchopulmonary dysplasia in preterm infants.


Assuntos
Displasia Broncopulmonar , Recém-Nascido Prematuro , Hemorragias Intracranianas , Surfactantes Pulmonares , Humanos , Surfactantes Pulmonares/administração & dosagem , Recém-Nascido , Estudos Prospectivos , Displasia Broncopulmonar/prevenção & controle , Displasia Broncopulmonar/tratamento farmacológico , Displasia Broncopulmonar/etiologia , Masculino , Feminino , Hemorragias Intracranianas/prevenção & controle , Hemorragias Intracranianas/induzido quimicamente
5.
Am J Nephrol ; 54(9-10): 359-369, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37437553

RESUMO

INTRODUCTION: Chronic kidney disease, which is defined by a reduced estimated glomerular filtration rate and albuminuria, imposes a large health burden worldwide. Ethnicity-specific associations are frequently observed in genome-wide association studies (GWAS). This study conducts a GWAS of albuminuria in the nondiabetic population of Taiwan. METHODS: Nondiabetic individuals aged 30-70 years without a history of cancer were enrolled from the Taiwan Biobank. A total of 6,768 subjects were subjected to a spot urine examination. After quality control using PLINK and imputation using SHAPEIT and IMPUTE2, a total of 3,638,350 single-nucleotide polymorphisms (SNPs) remained for testing. SNPs with a minor allele frequency of less than 0.1% were excluded. Linear regression was used to determine the relationship between SNPs and log urine albumin-to-creatinine ratio. RESULTS: Six suggestive loci are identified in or near the FCRL3 (p = 2.56 × 10-6), TMEM161 (p = 4.43 × 10-6), EFCAB1 (p = 2.03 × 10-6), ELMOD1 (p = 2.97 × 10-6), RYR3 (p = 1.34 × 10-6), and PIEZO2 (p = 2.19 × 10-7). Genetic variants in the FCRL3 gene that encode a secretory IgA receptor are found to be associated with IgA nephropathy, which can manifest as proteinuria. The PIEZO2 gene encodes a sensor for mechanical forces in mesangial cells and renin-producing cells. Five SNPs with a p-value between 5 × 10-6 and 5 × 10-5 are also identified in five genes that may have a biological role in the development of albuminuria. CONCLUSION: Five new loci and one known suggestive locus for albuminuria are identified in the nondiabetic Taiwanese population.


Assuntos
Glomerulonefrite por IGA , Insuficiência Renal Crônica , Humanos , Estudo de Associação Genômica Ampla , Albuminúria/genética , Albuminúria/epidemiologia , Testes de Função Renal , Polimorfismo de Nucleotídeo Único
6.
J Biomed Sci ; 30(1): 13, 2023 Feb 19.
Artigo em Inglês | MEDLINE | ID: mdl-36803854

RESUMO

BACKGROUND: Genome-wide association studies (GWASs) have linked RRBP1 (ribosomal-binding protein 1) genetic variants to atherosclerotic cardiovascular diseases and serum lipoprotein levels. However, how RRBP1 regulates blood pressure is unknown. METHODS: To identify genetic variants associated with blood pressure, we performed a genome-wide linkage analysis with regional fine mapping in the Stanford Asia-Pacific Program for Hypertension and Insulin Resistance (SAPPHIRe) cohort. We further investigated the role of the RRBP1 gene using a transgenic mouse model and a human cell model. RESULTS: In the SAPPHIRe cohort, we discovered that genetic variants of the RRBP1 gene were associated with blood pressure variation, which was confirmed by other GWASs for blood pressure. Rrbp1- knockout (KO) mice had lower blood pressure and were more likely to die suddenly from severe hyperkalemia caused by phenotypically hyporeninemic hypoaldosteronism than wild-type controls. The survival of Rrbp1-KO mice significantly decreased under high potassium intake due to lethal hyperkalemia-induced arrhythmia and persistent hypoaldosteronism, which could be rescued by fludrocortisone. An immunohistochemical study revealed renin accumulation in the juxtaglomerular cells of Rrbp1-KO mice. In the RRBP1-knockdown Calu-6 cells, a human renin-producing cell line, transmission electron and confocal microscopy revealed that renin was primarily retained in the endoplasmic reticulum and was unable to efficiently target the Golgi apparatus for secretion. CONCLUSIONS: RRBP1 deficiency in mice caused hyporeninemic hypoaldosteronism, resulting in lower blood pressure, severe hyperkalemia, and sudden cardiac death. In juxtaglomerular cells, deficiency of RRBP1 reduced renin intracellular trafficking from ER to Golgi apparatus. RRBP1 is a brand-new regulator of blood pressure and potassium homeostasis discovered in this study.


Assuntos
Proteínas de Transporte , Hiperpotassemia , Hipertensão , Hipoaldosteronismo , Animais , Humanos , Camundongos , Aldosterona , Óxido de Alumínio , Pressão Sanguínea , Estudo de Associação Genômica Ampla , Homeostase , Hiperpotassemia/complicações , Hipoaldosteronismo/complicações , Potássio , Renina/genética , Proteínas de Transporte/genética , Proteínas de Transporte/fisiologia
7.
J Bacteriol ; 202(18)2020 08 25.
Artigo em Inglês | MEDLINE | ID: mdl-32661076

RESUMO

Vibrio cholerae biofilm biogenesis, which is important for survival, dissemination, and persistence, requires multiple genes in the Vibrio polysaccharides (vps) operons I and II as well as the cluster of ribomatrix (rbm) genes. Transcriptional control of these genes is a complex process that requires several activators/repressors and the ubiquitous signaling molecule, cyclic di-GMP (c-di-GMP). Previously, we demonstrated that VpsR directly activates RNA polymerase containing σ70 (σ70-RNAP) at the vpsL promoter (P vpsL ), which precedes the vps-II operon, in a c-di-GMP-dependent manner by stimulating formation of the transcriptionally active, open complex. Using in vitro transcription, electrophoretic mobility shift assays, and DNase I footprinting, we show here that VpsR also directly activates σ70-RNAP transcription from other promoters within the biofilm formation cluster, including P vpsU , at the beginning of the vps-I operon, P rbmA , at the start of the rbm cluster, and P rbmF , which lies upstream of the divergent rbmF and rbmE genes. In this capacity, we find that VpsR is able to behave both as a class II activator, which functions immediately adjacent/overlapping the core promoter sequence (P vpsL and P vpsU ), and as a class I activator, which functions farther upstream (P rbmA and P rbmF ). Because these promoters vary in VpsR-DNA binding affinity in the absence and presence of c-di-GMP, we speculate that VpsR's mechanism of activation is dependent on both the concentration of VpsR and the level of c-di-GMP to increase transcription, resulting in finely tuned regulation.IMPORTANCEVibrio cholerae, the bacterial pathogen that is responsible for the disease cholera, uses biofilms to aid in survival, dissemination, and persistence. VpsR, which directly senses the second messenger c-di-GMP, is a major regulator of this process. Together with c-di-GMP, VpsR directly activates transcription by RNA polymerase containing σ70 from the vpsL biofilm biogenesis promoter. Using biochemical methods, we demonstrate for the first time that VpsR/c-di-GMP directly activates σ70-RNA polymerase at the first genes of the vps and ribomatrix operons. In this regard, it functions as either a class I or class II activator. Our results broaden the mechanism of c-di-GMP-dependent transcription activation and the specific role of VpsR in biofilm formation.


Assuntos
Proteínas de Bactérias/metabolismo , Biofilmes , GMP Cíclico/metabolismo , RNA Polimerases Dirigidas por DNA/metabolismo , Fator sigma/metabolismo , Vibrio cholerae/genética , Proteínas de Bactérias/genética , Regulação Bacteriana da Expressão Gênica , Óperon , Regiões Promotoras Genéticas
8.
Nucleic Acids Res ; 46(17): 8876-8887, 2018 09 28.
Artigo em Inglês | MEDLINE | ID: mdl-30007313

RESUMO

The small molecule cyclic di-GMP (c-di-GMP) is known to affect bacterial gene expression in myriad ways. In Vibrio cholerae in vivo, the presence of c-di-GMP together with the response regulator VpsR results in transcription from PvpsL, a promoter of biofilm biosynthesis genes. VpsR shares homology with enhancer binding proteins that activate σ54-RNA polymerase (RNAP), but it lacks conserved residues needed to bind to σ54-RNAP and to hydrolyze adenosine triphosphate, and PvpsL transcription does not require σ54 in vivo. Consequently, the mechanism of this activation has not been clear. Using an in vitro transcription system, we demonstrate activation of PvspL in the presence of VpsR, c-di-GMP and σ70-RNAP. c-di-GMP does not significantly change the affinity of VpsR for PvpsL DNA or the DNase I footprint of VpsR on the DNA, and it is not required for VpsR to dimerize. However, DNase I and KMnO4 footprints reveal that the σ70-RNAP/VpsR/c-di-GMP complex on PvpsL adopts a different conformation from that formed by σ70-RNAP alone, with c-di-GMP or with VpsR. Our results suggest that c-di-GMP is required for VpsR to generate the specific protein-DNA architecture needed for activated transcription, a previously unrecognized role for c-di-GMP in gene expression.


Assuntos
Proteínas de Bactérias/fisiologia , Biofilmes/crescimento & desenvolvimento , GMP Cíclico/análogos & derivados , Proteínas de Ligação a DNA/fisiologia , Regulação Bacteriana da Expressão Gênica/genética , Regiões Promotoras Genéticas/genética , Iniciação da Transcrição Genética , Vibrio cholerae/genética , Proteínas de Bactérias/química , Proteínas de Bactérias/genética , GMP Cíclico/fisiologia , Pegada de DNA , DNA Bacteriano/genética , DNA Bacteriano/metabolismo , Proteínas de Ligação a DNA/química , Proteínas de Ligação a DNA/genética , RNA Polimerases Dirigidas por DNA/metabolismo , Ativação Enzimática , Ligação Proteica , Fator sigma/metabolismo , Relação Estrutura-Atividade , Vibrio cholerae/metabolismo
9.
J Insect Sci ; 20(1)2020 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-31899494

RESUMO

Mamestra brassicae L. is an important, regionally migratory pest of vegetable crops in Europe and Asia. Its migratory activity contributes significantly to population outbreaks, causing severe crop yield losses. Because an in-depth understanding of flight performance is key to revealing migratory patterns, here we used a computer-linked flight mill and stroboscope to study the flight ability and wingbeat frequency (WBF) of M. brassicae in relation to sex, age, temperature, and relative humidity (RH). The results showed that age significantly affected the flight ability and WBF of M. brassicae, and 3-d-old individuals performed the strongest performance (total flight distance: 45.6 ± 2.5 km; total flight duration: 9.3 ± 0.3 h; WBF: 44.0 ± 0.5 Hz at 24°C and 75% RH). The age for optimal flight was considered to be 2-3 d old. Temperature and RH also significantly affected flight ability and WBF; flight was optimal from 23°C to 25°C and 64-75% RH. Because M. brassicae thus has great potential to undertake long-distance migration, better knowledge of its flight behavior and migration will help establish a pest forecasting and early-warning system.


Assuntos
Voo Animal , Mariposas/fisiologia , Asas de Animais/fisiologia , Fatores Etários , Animais , Feminino , Umidade , Masculino , Fatores Sexuais , Temperatura
10.
Oncologist ; 24(12): 1534-1542, 2019 12.
Artigo em Inglês | MEDLINE | ID: mdl-31292272

RESUMO

BACKGROUND: The form of microsatellite instability (MSI) affecting tetranucleotide repeats known as elevated microsatellite alterations at selected tetranucleotide repeats (EMAST) has emerged as a new potential biomarker in multiple cancers. In colorectal cancer (CRC), the correlation between EMAST and MSI mutations remain inconclusive. MATERIALS AND METHODS: We evaluated 1,505 patients with CRC using five EMAST markers (D20S82, D20S85, D8S321, D9S242, and MYCL1) and the Bethesda panel of MSI markers. Most commonly, mutations involved in CRCs were identified by MassArray Assay, and DNA repair genes were analyzed by next-generation sequencing. Clinical characteristics and prognostic relevance were correlated with EMAST and MSI. RESULTS: Tumors that were EMAST positive and MSI high (MSI-H) were detected in 159 (10.6%) and 154 (10.2%) of 1,505 patients with CRC. Patients were divided into four groups according to EMAST and MSI status (EMAST-positive and MSI-H, EMAST-positive and microsatellite-stable [MSS], EMAST-negative and MSI-H, and EMAST-negative and MSS). The EMAST-positive and MSI-H group was associated with female predominance, higher prevalence of proximal colon tumors, early stage tumors, poorly differentiated tumors, mucinous histology, and higher incidence of mutations in PI3KCA, BRAF, TGFBR, PTEN, and AKT1 compared with other groups. Furthermore, compared with only EMAST-positive tumors or only MSI-H tumors, tumors that were both EMAST-positive and MSI-H had a higher frequency of MLH1, MSH3, MSH6, PMS2, and EXO1 gene mutations. Finally, the presence of EMAST-positive and MSI-H tumors was a good prognostic indicator in CRC. CONCLUSION: High mutations in several DNA repair genes in EMAST-positive and MSI-H tumors suggest that this subtype of CRC might be more suitable for treatment with immune therapy. IMPLICATIONS FOR PRACTICE: Elevated microsatellite alterations at selected tetranucleotide repeats (EMAST) is a unique molecular subtype of colorectal cancer (CRC). The current study demonstrated that the EMAST-positive and MSI-high (MSI-H) group was associated with female predominance, higher prevalence of proximal colon tumors, early stage tumors, poorly differentiated tumors, mucinous histology, and higher incidence of mutations in PI3KCA, BRAF, TGFBR, PTEN, and AKT1 compared with other groups. Most importantly, high mutations in DNA repair genes and MSI-related genes in EMAST-positive and MSI-H tumors suggest that this subtype of CRC might be more suitable for treatment with immune therapy compared with MSI-H tumors alone.


Assuntos
Neoplasias Colorretais/genética , Instabilidade de Microssatélites , Repetições de Microssatélites/genética , Biomarcadores Tumorais , Neoplasias Colorretais/patologia , Humanos , Prognóstico
11.
Am J Nephrol ; 49(1): 41-51, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30557878

RESUMO

BACKGROUND: Extensive studies have demonstrated that sleep is an important modulator of cardiovascular and metabolic diseases. However, its impact on renal function remains uncertain. METHODS: A total of 26,249 adults aged ≥20 years were recruited through voluntary health examinations in Taiwan. Sleep duration was self-reported by questionnaire. Proteinuria was graded semi-quantitatively by dipstick urine test. The associations of sleep duration with proteinuria and estimated glomerular filtration rate (eGFR) were analyzed. RESULTS: After an average follow-up period of 2.62 years, the crude hazard ratio (HR) for proteinuria progression were 1.92 (95% CI 1.22-3.03), 1.23 (95% CI 1.09-1.39), and 1.18 (95% CI 1.00-1.39) for those with sleep duration < 4, 4-6, and > 8 h compared to those with sleep duration of 6-8 h (the reference group), respectively. The HR remained significant for those with sleep duration < 4 h (adjusted HR 1.65 [95% CI 1.05-2.61]) and 4-6 h (adjusted HR 1.19 [95% CI 1.06-1.35]) after adjustment for age, sex, blood pressure, fasting glucose, body mass index, cholesterols, triglycerides, uric acids, physical activity, smoking, alcohol consumption, income/educational levels, and baseline eGFR. However, eGFR was not significantly different among different sleep duration groups. DISCUSSION: This result indicates short sleep duration is independently associated with the progression of proteinuria.


Assuntos
Taxa de Filtração Glomerular/fisiologia , Proteinúria/fisiopatologia , Sono/fisiologia , Adulto , Progressão da Doença , Feminino , Seguimentos , Humanos , Masculino , Pessoa de Meia-Idade , Proteinúria/diagnóstico , Proteinúria/urina , Autorrelato/estatística & dados numéricos , Taiwan , Fatores de Tempo , Adulto Jovem
12.
J Insect Sci ; 19(1)2019 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-30690535

RESUMO

Cryptochromes act as photoreceptors or integral components of the circadian clock that involved in the regulation of circadian clock and regulation of migratory activity in many animals, and they may also act as magnetoreceptors that sensed the direction of the Earth's magnetic field for the purpose of navigation during animals' migration. Light is a major environmental signal for insect circadian rhythms, and it is also necessary for magnetic orientation. We identified the full-length cDNA encoding As-CRY1 and As-CRY2 in Agrotis segetum Denis and Schiffermaller (turnip moth (Lepidoptera: Noctuidae)). The DNA photolyase domain and flavin adenine dinucleotide-binding domain were found in both cry genes, and multiple alignments showed that those domains that are important for the circadian clock and magnetosensing were highly conserved among different animals. Quantitative polymerase chain reaction showed that cry genes were expressed in all examined body parts, with higher expression in adults during the developmental stages of the moths. Under a 14:10 (L:D) h cycle, the expression of cry genes showed a daily biological rhythm, and light can affect the expression levels of As-cry genes. The expression levels of cry genes were higher in the migratory population than in the reared population and higher in the emigration population than in the immigration population. These findings suggest that the two cryptochrome genes characterized in the turnip moth might be associated with the circadian clock and magnetosensing. Their functions deserve further study, especially for potential control of the turnip moth.


Assuntos
Migração Animal/fisiologia , Criptocromos/genética , Mariposas/genética , Animais , Relógios Circadianos/fisiologia , Criptocromos/metabolismo , Feminino , Luz , Fenômenos Magnéticos , Masculino , Mariposas/fisiologia , Transcriptoma/fisiologia , Transcriptoma/efeitos da radiação
13.
J Bacteriol ; 200(7)2018 04 01.
Artigo em Inglês | MEDLINE | ID: mdl-29311281

RESUMO

3',5'-Cyclic diguanylic acid (c-di-GMP) is a bacterial second messenger molecule that is a key global regulator in Vibrio cholerae, but the molecular mechanisms by which this molecule regulates downstream phenotypes have not been fully characterized. One such regulatory factor that may respond to c-di-GMP is the Vc2 c-di-GMP-binding riboswitch that is hypothesized to control the expression of the downstream putative transcription factor TfoY. Although much is known about the physical and structural properties of the Vc2 riboswitch aptamer, the nature of its expression and function in V. cholerae has not been investigated. Here, we show that Vc2 functions as an off switch to inhibit TfoY production at intermediate and high concentrations of c-di-GMP. At low c-di-GMP concentrations, TfoY production is induced to stimulate dispersive motility. We also observed increased transcription of tfoY at high intracellular concentrations of c-di-GMP, but this induction is independent of the Vc2 riboswitch and occurs via transcriptional control of promoters upstream of tfoY by the previously identified c-di-GMP dependent transcription factor VpsR. Our results show that TfoY is induced by c-di-GMP at both low and high intracellular concentrations of c-di-GMP via posttranscriptional and transcriptional mechanisms, respectively. This regulation contributes to the formation of three distinct c-di-GMP signaling states in V. choleraeIMPORTANCE The bacterial pathogen Vibrio cholerae must transition between life in aquatic environmental reservoirs and life in the gastrointestinal tract. Biofilm formation and bacterial motility, and their control by the second messenger molecule c-di-GMP, play integral roles in this adaptation. Here, we define the third major mechanism by which c-di-GMP controls bacterial motility. This pathway utilizes a noncoding RNA element known as a riboswitch that, when bound to c-di-GMP, inhibits the expression of the transcription factor TfoY. TfoY production switches V. cholerae motility from a dense to a dispersive state. Our results suggest that the c-di-GMP signaling network of V. cholerae can exist in at least three distinct states to regulate biofilm formation and motility.


Assuntos
Proteínas de Bactérias/genética , GMP Cíclico/análogos & derivados , Regulação Bacteriana da Expressão Gênica , Fatores de Transcrição/genética , Transcrição Gênica , Vibrio cholerae/genética , Biofilmes , GMP Cíclico/genética , Movimento , Regiões Promotoras Genéticas , Processamento de Proteína Pós-Traducional/genética , Riboswitch/genética , Transdução de Sinais/genética , Vibrio cholerae/fisiologia
14.
Nucleic Acids Res ; 44(16): 7974-88, 2016 09 19.
Artigo em Inglês | MEDLINE | ID: mdl-27458207

RESUMO

The ability of RNA polymerase (RNAP) to select the right promoter sequence at the right time is fundamental to the control of gene expression in all organisms. However, there is only one crystallized structure of a complete activator/RNAP/DNA complex. In a process called σ appropriation, bacteriophage T4 activates a class of phage promoters using an activator (MotA) and a co-activator (AsiA), which function through interactions with the σ(70) subunit of RNAP. We have developed a holistic, structure-based model for σ appropriation using multiple experimentally determined 3D structures (Escherichia coli RNAP, the Thermus aquaticus RNAP/DNA complex, AsiA /σ(70) Region 4, the N-terminal domain of MotA [MotA(NTD)], and the C-terminal domain of MotA [MotA(CTD)]), molecular modeling, and extensive biochemical observations indicating the position of the proteins relative to each other and to the DNA. Our results visualize how AsiA/MotA redirects σ, and therefore RNAP activity, to T4 promoter DNA, and demonstrate at a molecular level how the tactful interaction of transcriptional factors with even small segments of RNAP can alter promoter specificity. Furthermore, our model provides a rational basis for understanding how a mutation within the ß subunit of RNAP (G1249D), which is far removed from AsiA or MotA, impairs σ appropriation.


Assuntos
Bacteriófago T4/metabolismo , RNA Polimerases Dirigidas por DNA/metabolismo , DNA/genética , Escherichia coli/enzimologia , Escherichia coli/genética , Transcrição Gênica , Sequência de Aminoácidos , Fenômenos Biofísicos , Reagentes de Ligações Cruzadas/metabolismo , Proteínas de Escherichia coli/química , Proteínas de Escherichia coli/metabolismo , Luz , Modelos Moleculares , Peptídeos/química , Regiões Promotoras Genéticas
15.
J Mater Sci Mater Med ; 29(7): 100, 2018 06 26.
Artigo em Inglês | MEDLINE | ID: mdl-29946882

RESUMO

The original version of this article unfortunately contained a mistake. The country was incorrect in the authors affiliations. It should read as "ROC". The corrected affiliations are given below.

16.
Molecules ; 23(3)2018 Mar 07.
Artigo em Inglês | MEDLINE | ID: mdl-29518973

RESUMO

Chamaecyparis formosensis is Taiwan's most representative tree, and has high economic value. To date, only a few active chemical constituents have been reported for C. formosensis. In this study, 37 secondary metabolites, including three new compounds (1-3), were extracted from the leaves of C. formosensis. The compounds isolated from the ethyl acetate layer were used at different concentrations to treat HT-1080 human fibrosarcoma cells and to evaluate their effects on matrix metalloprotease 2 (MMP-2) and 9 (MMP-9) expression. Based on extensive analysis of data from high-resolution mass spectrometry (HR-MS) as well as nuclear magnetic resonance (NMR), infrared (IR), and ultraviolet (UV) spectroscopy, the new compounds were identified as 11,12-dihydroxyisodaucenoic acid (1), 12-hydroxyisodaucenoic acid (2), and 1-oxo-2α,3ß-dihydroxytotarol (3). Known compounds 4-37 were identified by comparing their spectroscopic data with data reported in the literature. Biological activity tests by gelatin zymographic analysis revealed that seven compounds, including new compound 2, have no cytotoxic effect on HT-1080 cells and were found to increase MMP-2 or MMP-9 expression by 1.25- to 1.59-fold at lower concentrations of 10-50 µM. These naturally derived regulatory compounds could potentially serve as a novel pharmaceutical basis for medical purposes.


Assuntos
Chamaecyparis/química , Extratos Vegetais/química , Extratos Vegetais/farmacologia , Folhas de Planta/química , Terpenos/química , Terpenos/farmacologia , Linhagem Celular , Ativação Enzimática , Regulação da Expressão Gênica/efeitos dos fármacos , Humanos , Espectroscopia de Ressonância Magnética , Metaloproteinase 2 da Matriz/genética , Metaloproteinase 2 da Matriz/metabolismo , Metaloproteinase 9 da Matriz/genética , Metaloproteinase 9 da Matriz/metabolismo , Estrutura Molecular , Extratos Vegetais/isolamento & purificação , Terpenos/isolamento & purificação
17.
J Mater Sci Mater Med ; 28(12): 192, 2017 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-29143185

RESUMO

Stem cells derived from oral tissue represent a highly attractive alternative source for clinical bone regeneration because they can be collected by non-invasive or minimally invasive procedures. Herein, we describe the human dental stem cells (DSCs) deriving from buccal fat pads (BFP), dental pulp (DP) of impacted teeth, and periodontal ligaments (PDL) to obtain BFPSCs, DPSCs, and PDLSCs, respectively. Cells were purified with selected medium and expanded through passages in stem cell culture medium. Purified cells were characterized for stemness by their growth rate, immunostaining, and multilineage differentiation ability. They showed plastic adherence, expression of stemness-specific markers, and multilineage differentiation potential. Immunocytochemistry analysis confirmed that DPSCs had more osteogenic potential than BFSCs and PDLSCs. Calcium-rich deposits, evaluated by von Kossa and Alizarin red staining, showed greater mineralization when DPSCs were cultured on collagen type I matrix than without collagen. Furthermore, DPSC-seeded collagen type I matrix maintained consistent osteogenesis and boosted mineral formation by 1-2 weeks over that in DPSCs cultured without collagen. Radiographic analysis of DPSC-seeded collagen type I matrix transplanted into rat cranial defects showed significant bone regeneration after 8 weeks. These results suggested that the redundant oral tissue can be used as a source of adult multipotent stem cells for clinical bone regeneration. Triple overlay images with biomarkers (red), nuclei (blue) and bright field morphology of DPSCs. The specifically osteo-differentiation shown by osteocalcin (left) expression and lack of sox9 (right) expressed in the images below which were cultured with collagen matrix, contrast with no collagen matrix group above.


Assuntos
Tecido Adiposo/citologia , Colágeno Tipo I , Polpa Dentária/citologia , Osteogênese/fisiologia , Ligamento Periodontal/citologia , Células-Tronco/fisiologia , Animais , Transplante Ósseo , Técnicas de Cultura de Células , Humanos , Ratos
18.
J Formos Med Assoc ; 116(1): 41-48, 2017 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-26879838

RESUMO

BACKGROUND/PURPOSE: Cancer stem cells (CSCs) are deemed as the driving force of tumorigenesis in oral squamous cell carcinomas (OSCCs). In this study, we investigated the chemotherapeutic effect of sulforaphane, a dietary component from broccoli sprouts, on targeting OSCC-CSCs. METHODS: The effect of sulforaphane on normal oral epithelial cells (SG) and sphere-forming OSCC-CSCs isolated from SAS and GNM cells was examined. ALDH1 activity and CD44 positivity of OSCC-CSCs with sulforaphane treatment was assessed by flow cytometry analysis. In vitro and in vivo tumorigenicity assays of OSCC-CSCs with sulforaphane treatment were presented. RESULTS: We observed that the sulforaphane dose-dependently eliminated the proliferation rate of OSCC-CSCs, whereas the inhibition on SG cells proliferation was limited. Cancer stemness properties including self-renewal, CD44 positivity, and ALDH1 activity were also decreased in OSCC-CSCs with different doses of sulforaphane treatment. Moreover, sulforaphane treatment of OSCC-CSCs decreased the migration, invasion, clonogenicity, and in vivo tumorigenicity of xenograghts. Sulforaphane treatment resulted in a dose-dependent increase in the levels of tumor suppressive miR200c. CONCLUSION: These lines of evidence suggest that sulforaphane can suppress the cancer stemness and tumor-initiating properties in OSCC-CSCs both in vitro and in vivo.


Assuntos
Anticarcinógenos/administração & dosagem , Carcinoma de Células Escamosas/tratamento farmacológico , Isotiocianatos/administração & dosagem , MicroRNAs/metabolismo , Neoplasias Bucais/tratamento farmacológico , Células-Tronco Neoplásicas/efeitos dos fármacos , Família Aldeído Desidrogenase 1 , Animais , Carcinoma de Células Escamosas/patologia , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Suplementos Nutricionais , Modelos Animais de Doenças , Humanos , Receptores de Hialuronatos/metabolismo , Isoenzimas/metabolismo , Camundongos , Camundongos Nus , Neoplasias Bucais/patologia , Retinal Desidrogenase/metabolismo , Sulfóxidos
19.
J Nat Prod ; 78(10): 2346-54, 2015 Oct 23.
Artigo em Inglês | MEDLINE | ID: mdl-26461164

RESUMO

Pandanus amaryllifolius Roxb. (Pandanaceae) is used as a flavor and in folk medicine in Southeast Asia. The ethanolic crude extract of the aerial parts of P. amaryllifolius exhibited antioxidant, antibiofilm, and anti-inflammatory activities in previous studies. In the current investigation, the purification of the ethanolic extract yielded nine new compounds, including N-acetylnorpandamarilactonines A (1) and B (2); pandalizines A (3) and B (4); pandanmenyamine (5); pandamarilactones 2 (6) and 3 (7), and 5(E)-pandamarilactonine-32 (8); and pandalactonine (9). The isolated alkaloids, with either a γ-alkylidene-α,ß-unsaturated-γ-lactone or γ-alkylidene-α,ß-unsaturated-γ-lactam system, can be classified into five skeletons including norpandamarilactonine, indolizinone, pandanamine, pandamarilactone, and pandamarilactonine. A plausible biosynthetic route toward 1-5, 7, and 9 is proposed.


Assuntos
Alcaloides/isolamento & purificação , Alcaloides/metabolismo , Pandanaceae/química , Alcaloides/química , Antioxidantes/química , Antioxidantes/isolamento & purificação , Antioxidantes/metabolismo , Furanos/química , Furanos/isolamento & purificação , Furanos/metabolismo , Lactonas/química , Lactonas/isolamento & purificação , Lactonas/metabolismo , Estrutura Molecular , Ressonância Magnética Nuclear Biomolecular , Componentes Aéreos da Planta/química , Folhas de Planta/química , Pirrolidinas/química , Pirrolidinas/isolamento & purificação , Pirrolidinas/metabolismo , Estereoisomerismo , Taiwan
20.
Sensors (Basel) ; 15(3): 6560-85, 2015 Mar 19.
Artigo em Inglês | MEDLINE | ID: mdl-25808764

RESUMO

Spatial information plays a critical role in remote sensing and mapping applications such as environment surveying and disaster monitoring. An Unmanned Aerial Vehicle (UAV)-borne mobile mapping system (MMS) can accomplish rapid spatial information acquisition under limited sky conditions with better mobility and flexibility than other means. This study proposes a long endurance Direct Geo-referencing (DG)-based fixed-wing UAV photogrammetric platform and two DG modules that each use different commercial Micro-Electro Mechanical Systems' (MEMS) tactical grade Inertial Measurement Units (IMUs). Furthermore, this study develops a novel kinematic calibration method which includes lever arms, boresight angles and camera shutter delay to improve positioning accuracy. The new calibration method is then compared with the traditional calibration approach. The results show that the accuracy of the DG can be significantly improved by flying at a lower altitude using the new higher specification hardware. The new proposed method improves the accuracy of DG by about 20%. The preliminary results show that two-dimensional (2D) horizontal DG positioning accuracy is around 5.8 m at a flight height of 300 m using the newly designed tactical grade integrated Positioning and Orientation System (POS). The positioning accuracy in three-dimensions (3D) is less than 8 m.

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