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1.
Nature ; 566(7744): 344-349, 2019 02.
Artigo em Inglês | MEDLINE | ID: mdl-30700907

RESUMO

Fibroblasts are polymorphic cells with pleiotropic roles in organ morphogenesis, tissue homeostasis and immune responses. In fibrotic diseases, fibroblasts synthesize abundant amounts of extracellular matrix, which induces scarring and organ failure. By contrast, a hallmark feature of fibroblasts in arthritis is degradation of the extracellular matrix because of the release of metalloproteinases and degrading enzymes, and subsequent tissue destruction. The mechanisms that drive these functionally opposing pro-fibrotic and pro-inflammatory phenotypes of fibroblasts remain unknown. Here we identify the transcription factor PU.1 as an essential regulator of the pro-fibrotic gene expression program. The interplay between transcriptional and post-transcriptional mechanisms that normally control the expression of PU.1 expression is perturbed in various fibrotic diseases, resulting in the upregulation of PU.1, induction of fibrosis-associated gene sets and a phenotypic switch in extracellular matrix-producing pro-fibrotic fibroblasts. By contrast, pharmacological and genetic inactivation of PU.1 disrupts the fibrotic network and enables reprogramming of fibrotic fibroblasts into resting fibroblasts, leading to regression of fibrosis in several organs.


Assuntos
Diferenciação Celular/genética , Fibroblastos/metabolismo , Fibroblastos/patologia , Fibrose/genética , Fibrose/patologia , Proteínas Proto-Oncogênicas/metabolismo , Transativadores/metabolismo , Animais , Sequência de Bases , Epigênese Genética , Feminino , Humanos , Inflamação/genética , Inflamação/patologia , Masculino , Camundongos , Regiões Promotoras Genéticas/genética , Proteínas Proto-Oncogênicas/antagonistas & inibidores , Transativadores/antagonistas & inibidores
2.
Postgrad Med J ; 100(1181): 142-150, 2024 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-38055906

RESUMO

BACKGROUND: Contrast-induced nephropathy has become increasingly prevalent as the age and prevalence of comorbidities in the general population have increased. Most cases of contrast-induced nephropathy are reversible; however, some may progress to acute kidney disease, and subsequently, to chronic kidney disease. Sodium-glucose cotransporter 2 inhibitors (SGLT2i) are known for their renoprotective effects. However, whether the use of these inhibitors affects the risk of contrast-induced kidney injury remains unclear. METHODS: Data were collected from the Taipei Medical University Clinical Research Database. We included patients with diabetes who had contrast exposure between 2016 and 2020 because of computed tomography or coronary angiography. The primary outcome was the risk of a major adverse kidney event (MAKE), which encompassed acute kidney disease, chronic kidney disease progression, and the need for renal replacement therapy. Overlap weighting was performed to reduce the effects of potential confounders. RESULTS: This study included 12 421 patients, who were divided into two groups: SGLT2i users (n = 920) and nonusers (n = 11 501). The follow-up period after contrast exposure was 6 months. The risk of a MAKE was lower in SGLT2i users than in nonusers (incidence, 36.9 vs. 49.9 per 1000 person-months, respectively; P = .0011). Furthermore, the incidence of acute kidney disease or chronic kidney disease progression was significantly lower in the SGLT2i users than in nonusers. However, no significant between-group difference was noted in the incidence of other MAKEs. CONCLUSIONS: SGLT2i may be safely used in diabetic patients needing contrast exposure. The risk of a MAKE may be lower in SGLT2i users than in nonusers.


Assuntos
Diabetes Mellitus Tipo 2 , Insuficiência Renal Crônica , Inibidores do Transportador 2 de Sódio-Glicose , Humanos , Diabetes Mellitus Tipo 2/tratamento farmacológico , Diabetes Mellitus Tipo 2/epidemiologia , Inibidores do Transportador 2 de Sódio-Glicose/efeitos adversos , Rim , Insuficiência Renal Crônica/induzido quimicamente , Insuficiência Renal Crônica/epidemiologia , Glucose , Sódio , Estudos Retrospectivos
3.
Blood ; 137(17): 2403-2416, 2021 04 29.
Artigo em Inglês | MEDLINE | ID: mdl-33529322

RESUMO

Chronic graft-versus-host disease (cGVHD) is a major life-threatening complication of allogeneic hematopoietic stem cell transplantation. The molecular mechanisms underlying cGVHD remain poorly understood, and targeted therapies for clinical use are not well established. Here, we examined the role of the canonical WNT pathway in sclerodermatous cGVHD (sclGVHD). WNT signaling was activated in human sclGVHD with increased nuclear accumulation of the transcription factor ß-catenin and a WNT-biased gene expression signature in lesional skin. Treatment with the highly selective tankryase inhibitor G007-LK, the CK1α agonist pyrvinium, or the LRP6 inhibitor salinomycin abrogated the activation of WNT signaling and protected against experimental cGVHD, without a significant impact on graft-versus-leukemia effect (GVL). Treatment with G007-LK, pyrvinium, or salinomycin almost completely prevented the development of clinical and histological features in the B10.D2 (H-2d) → BALB/c (H-2d) and LP/J (H-2b) → C57BL/6 (H-2b) models of sclGVHD. Inhibition of canonical WNT signaling reduced the release of extracellular matrix from fibroblasts and reduced leukocyte influx, suggesting that WNT signaling stimulates fibrotic tissue remodeling by direct effects on fibroblasts and by indirect inflammation-dependent effects in sclGVHD. Our findings may have direct translational potential, because pyrvinium is in clinical use, and tankyrase inhibitors are in clinical trials for other indications.


Assuntos
Doença Enxerto-Hospedeiro/prevenção & controle , Transplante de Células-Tronco Hematopoéticas/efeitos adversos , Piranos/farmacologia , Compostos de Pirvínio/farmacologia , Escleroderma Sistêmico/prevenção & controle , Sulfonas/farmacologia , Triazóis/farmacologia , Via de Sinalização Wnt/efeitos dos fármacos , Animais , Antibacterianos/farmacologia , Feminino , Fibroblastos/efeitos dos fármacos , Fibroblastos/metabolismo , Fibroblastos/patologia , Doença Enxerto-Hospedeiro/etiologia , Doença Enxerto-Hospedeiro/metabolismo , Doença Enxerto-Hospedeiro/patologia , Humanos , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Pessoa de Meia-Idade , Escleroderma Sistêmico/etiologia , Escleroderma Sistêmico/metabolismo , Escleroderma Sistêmico/patologia
4.
Exp Cell Res ; 417(2): 113219, 2022 08 15.
Artigo em Inglês | MEDLINE | ID: mdl-35643179

RESUMO

Induction of differentiation sensitizes chronic myeloid leukemia (CML) cells to the BCR-ABL inhibitor imatinib by mechanisms that remain unknown. We previously identified the BCR-ABL downstream effector CD69 which inhibits imatinib-induced CML cell differentiation. Herein, we found that the erythroid differentiation inducers activin A and aclacinomycin A induced expression of erythroid markers (α-globin, ζ-globin, GATA-1, and glycophorin A) and simultaneously reduced CD69 levels in K562 CML cells. Blockade of p38MAPK by SB203580 and shRNA eliminated the inhibitory effect of activin A on the promoter, mRNA, and protein levels and positive cell population of CD69. CD69 overexpression inhibited activin A-induced erythroid marker expression. Pretreatment of K562 cells with activin A to induce differentiation followed by a subtoxic concentration of imatinib caused growth inhibition and apoptosis that was reduced by CD69 overexpression. Activin A also reduced the expression of CD69's potential downstream molecule metallothionein 2A (MT2A) via p38MAPK. MT2A-knockdown reduced CD69 inhibition of activin A-induced erythroid marker expression. Furthermore, MT2A-knockdown reduced CD69 inhibition of activin A-imatinib sequential treatment-mediated growth inhibition and apoptosis in K562 and BCR-ABL-expressing CD34+ cells. These results suggest that CD69 inhibits activin A induction of erythroid differentiation-mediated CML cell sensitivity to imatinib via MT2A. Therefore, activin A induction of erythroid differentiation sensitizes BCR-ABL-positive cells to imatinib by downregulating the erythroid differentiation suppressors CD69 and MT2A.


Assuntos
Leucemia Mielogênica Crônica BCR-ABL Positiva , Proteínas Quinases p38 Ativadas por Mitógeno , Ativinas , Antígenos CD/metabolismo , Antígenos de Diferenciação de Linfócitos T/metabolismo , Apoptose , Diferenciação Celular , Resistencia a Medicamentos Antineoplásicos , Proteínas de Fusão bcr-abl/metabolismo , Humanos , Mesilato de Imatinib/farmacologia , Células K562 , Lectinas Tipo C/metabolismo , Leucemia Mielogênica Crônica BCR-ABL Positiva/tratamento farmacológico , Leucemia Mielogênica Crônica BCR-ABL Positiva/genética , Metalotioneína , Proteínas Quinases p38 Ativadas por Mitógeno/metabolismo
5.
Artigo em Inglês | MEDLINE | ID: mdl-37306629

RESUMO

BACKGROUND: The Skeletal Oncology Research Group machine-learning algorithm (SORG-MLA) was developed to predict the survival of patients with spinal metastasis. The algorithm was successfully tested in five international institutions using 1101 patients from different continents. The incorporation of 18 prognostic factors strengthens its predictive ability but limits its clinical utility because some prognostic factors might not be clinically available when a clinician wishes to make a prediction. QUESTIONS/PURPOSES: We performed this study to (1) evaluate the SORG-MLA's performance with data and (2) develop an internet-based application to impute the missing data. METHODS: A total of 2768 patients were included in this study. The data of 617 patients who were treated surgically were intentionally erased, and the data of the other 2151 patients who were treated with radiotherapy and medical treatment were used to impute the artificially missing data. Compared with those who were treated nonsurgically, patients undergoing surgery were younger (median 59 years [IQR 51 to 67 years] versus median 62 years [IQR 53 to 71 years]) and had a higher proportion of patients with at least three spinal metastatic levels (77% [474 of 617] versus 72% [1547 of 2151]), more neurologic deficit (normal American Spinal Injury Association [E] 68% [301 of 443] versus 79% [1227 of 1561]), higher BMI (23 kg/m2 [IQR 20 to 25 kg/m2] versus 22 kg/m2 [IQR 20 to 25 kg/m2]), higher platelet count (240 × 103/µL [IQR 173 to 327 × 103/µL] versus 227 × 103/µL [IQR 165 to 302 × 103/µL], higher lymphocyte count (15 × 103/µL [IQR 9 to 21× 103/µL] versus 14 × 103/µL [IQR 8 to 21 × 103/µL]), lower serum creatinine level (0.7 mg/dL [IQR 0.6 to 0.9 mg/dL] versus 0.8 mg/dL [IQR 0.6 to 1.0 mg/dL]), less previous systemic therapy (19% [115 of 617] versus 24% [526 of 2151]), fewer Charlson comorbidities other than cancer (28% [170 of 617] versus 36% [770 of 2151]), and longer median survival. The two patient groups did not differ in other regards. These findings aligned with our institutional philosophy of selecting patients for surgical intervention based on their level of favorable prognostic factors such as BMI or lymphocyte counts and lower levels of unfavorable prognostic factors such as white blood cell counts or serum creatinine level, as well as the degree of spinal instability and severity of neurologic deficits. This approach aims to identify patients with better survival outcomes and prioritize their surgical intervention accordingly. Seven factors (serum albumin and alkaline phosphatase levels, international normalized ratio, lymphocyte and neutrophil counts, and the presence of visceral or brain metastases) were considered possible missing items based on five previous validation studies and clinical experience. Artificially missing data were imputed using the missForest imputation technique, which was previously applied and successfully tested to fit the SORG-MLA in validation studies. Discrimination, calibration, overall performance, and decision curve analysis were applied to evaluate the SORG-MLA's performance. The discrimination ability was measured with an area under the receiver operating characteristic curve. It ranges from 0.5 to 1.0, with 0.5 indicating the worst discrimination and 1.0 indicating perfect discrimination. An area under the curve of 0.7 is considered clinically acceptable discrimination. Calibration refers to the agreement between the predicted outcomes and actual outcomes. An ideal calibration model will yield predicted survival rates that are congruent with the observed survival rates. The Brier score measures the squared difference between the actual outcome and predicted probability, which captures calibration and discrimination ability simultaneously. A Brier score of 0 indicates perfect prediction, whereas a Brier score of 1 indicates the poorest prediction. A decision curve analysis was performed for the 6-week, 90-day, and 1-year prediction models to evaluate their net benefit across different threshold probabilities. Using the results from our analysis, we developed an internet-based application that facilitates real-time data imputation for clinical decision-making at the point of care. This tool allows healthcare professionals to efficiently and effectively address missing data, ensuring that patient care remains optimal at all times. RESULTS: Generally, the SORG-MLA demonstrated good discriminatory ability, with areas under the curve greater than 0.7 in most cases, and good overall performance, with up to 25% improvement in Brier scores in the presence of one to three missing items. The only exceptions were albumin level and lymphocyte count, because the SORG-MLA's performance was reduced when these two items were missing, indicating that the SORG-MLA might be unreliable without these values. The model tended to underestimate the patient survival rate. As the number of missing items increased, the model's discriminatory ability was progressively impaired, and a marked underestimation of patient survival rates was observed. Specifically, when three items were missing, the number of actual survivors was up to 1.3 times greater than the number of expected survivors, while only 10% discrepancy was observed when only one item was missing. When either two or three items were omitted, the decision curves exhibited substantial overlap, indicating a lack of consistent disparities in performance. This finding suggests that the SORG-MLA consistently generates accurate predictions, regardless of the two or three items that are omitted. We developed an internet application (https://sorg-spine-mets-missing-data-imputation.azurewebsites.net/) that allows the use of SORG-MLA with up to three missing items. CONCLUSION: The SORG-MLA generally performed well in the presence of one to three missing items, except for serum albumin level and lymphocyte count (which are essential for adequate predictions, even using our modified version of the SORG-MLA). We recommend that future studies should develop prediction models that allow for their use when there are missing data, or provide a means to impute those missing data, because some data are not available at the time a clinical decision must be made. CLINICAL RELEVANCE: The results suggested the algorithm could be helpful when a radiologic evaluation owing to a lengthy waiting period cannot be performed in time, especially in situations when an early operation could be beneficial. It could help orthopaedic surgeons to decide whether to intervene palliatively or extensively, even when the surgical indication is clear.

6.
Molecules ; 29(1)2023 Dec 26.
Artigo em Inglês | MEDLINE | ID: mdl-38202720

RESUMO

Triazine herbicides are commonly used in agriculture to eliminate weeds. However, they can persist in the environment. In this study, we explored a new method for detecting triazine herbicides in aqueous samples. We selected two triazine herbicides, namely, prometryn and ametryn, as model herbicides. To generate magnetic probes, we mixed aqueous Gd3+ with aqueous sodium dodecyl sulfate (SDS), which created magnetic probes made of Gd3+-SDS micelles. These probes showed a trapping capacity for the model herbicides. Results indicated that the trapping capacities of our magnetic probes for ametryn and prometryn were approximately 466 and 468 nmol mg-1, respectively. The dissociation constants of our probes toward ametryn and prometryn were 2.92 × 10-5 and 1.27 × 10-5, respectively. This is the first report that the developed magnetic probes can be used to trap triazine herbicides. For detection, we used carbon fiber ionization mass spectrometry (CFI-MS), which can be used to directly detect semi-volatiles from the samples in the condensed phase. Because of the semi-volatility of triazine herbicides, the herbicides trapped by the magnetic probes can be directly analyzed by CFI-MS without any elution steps. In addition, we also demonstrated the feasibility of using our approach for detecting triazine herbicides in lake water and drinking water.

7.
Traffic ; 21(2): 231-249, 2020 02.
Artigo em Inglês | MEDLINE | ID: mdl-31622527

RESUMO

Model organisms are increasingly used to study and understand how neurofilament (NF)-based neurological diseases develop. However, whether a NF homolog exists in C. elegans remains unclear. We characterize TAG-63 as a NF-like protein with sequence homologies to human NEFH carrying various coiled coils as well as clustered phosphorylation sites. TAG-63 also exhibits features of NFL such as a molecular weight of around 70 kD, the lack of KSP repeats and the ability to form 10 nm filamentous structures in transmission electron micrographs. An anti-NEFH antibody detects a band at the predicted molecular weight of TAG-63 in Western blots of whole worm lysates and this band cannot be detected in tag-63 knockout worms. A transcriptional tag-63 reporter expresses in a broad range of neurons, and various anti-NFH antibodies stain worm neurons with an overlapping expression of axonal vesicle transporter UNC-104(KIF1A). Cultured neurons grow shorter axons when incubating with drugs known to disintegrate the NF network and rhodamine-labeled in vitro reconstituted TAG-63 filaments disintegrate upon drug exposure. Speeds of UNC-104 motors are diminished in tag-63 mutant worms with visibly increased accumulations of motors along axons. UNC-104/TAG-63 and SNB-1/TAG-63 not only colocalize in neurons but also revealed positive BiFC (bimolecular fluorescence assay) signals. In summary, we identified and characterized TAG-63 in C. elegans, and demonstrate that lack of this protein limits axonal transport efficiencies. Additionally, this study would aid in developing NF-related disease models in the future.


Assuntos
Transporte Axonal , Proteínas de Caenorhabditis elegans , Animais , Animais Geneticamente Modificados/fisiologia , Transporte Axonal/fisiologia , Caenorhabditis elegans/genética , Caenorhabditis elegans/fisiologia , Proteínas de Caenorhabditis elegans/fisiologia
8.
Anal Chem ; 94(51): 17779-17786, 2022 12 27.
Artigo em Inglês | MEDLINE | ID: mdl-36519823

RESUMO

Self-organization facilitates the formation of specific structures as a result of constituent interactions. In this study, the bottom of a 600 nm hole array photoresist template, which was deposited with a hydrophobic atom transfer radical polymerization (ATRP) initiator, was wetted by treatment with oxygen plasma. After the removal of the photoresist template, ring patterns of the ATRP initiator were formed at the interface between the hydrophobic and wetting regions. Poly[2-(dimethylamino)ethyl methacrylate] (PDMAEMA) was grafted from the ring array of the initiator to immobilize gold nanoparticles (AuNPs) as a uniform ring array on a silicon substrate via repeated swelling/shrinking cycles. The localized surface plasmon resonance (LSPR) peak of the PDMAEMA-AuNP hybrid ring (PAHR) red-shifted after 12 swelling/shrinking cycles. In comparison to gold nanoparticles, scalable gold nanorings can effectively develop a variety of nanostructures to design LSPR-based sensors and optimize the sensing accuracy and stability. To detect epithelial cell adhesion molecules (EpCAM) during the structural change from a ring to a disk, antiEpCAM was anchored onto the PAHR as a biosensor during swelling/shrinking. The coupling of antiEpCAM and EpCAM led to asymptotical convergence from rings to disks as well as blue shifts of the LSPR peaks. Linear correlation between the blue shift and EpCAM concentration showed a limit of detection of ∼27 pg mL-1 and a linear range of 25-200 pg mL-1 for the detection of EpCAM within 30 min. The simple method of combining lithography and plasma technology provides a versatile platform for developing the scalable ring structure of AuNPs for highly sensitive and selective biosensing.


Assuntos
Nanopartículas Metálicas , Ressonância de Plasmônio de Superfície , Ressonância de Plasmônio de Superfície/métodos , Ouro/química , Molécula de Adesão da Célula Epitelial , Nanopartículas Metálicas/química
9.
Proc Natl Acad Sci U S A ; 116(2): 566-574, 2019 01 08.
Artigo em Inglês | MEDLINE | ID: mdl-30587587

RESUMO

We report a patient who presented with congenital hypotonia, hypoventilation, and cerebellar histopathological alterations. Exome analysis revealed a homozygous mutation in the initiation codon of the NME3 gene, which encodes an NDP kinase. The initiation-codon mutation leads to deficiency in NME3 protein expression. NME3 is a mitochondrial outer-membrane protein capable of interacting with MFN1/2, and its depletion causes dysfunction in mitochondrial dynamics. Consistently, the patient's fibroblasts were characterized by a slow rate of mitochondrial dynamics, which was reversed by expression of wild-type or catalytic-dead NME3. Moreover, glucose starvation caused mitochondrial fragmentation and cell death in the patient's cells. The expression of wild-type and catalytic-dead but not oligomerization-attenuated NME3 restored mitochondrial elongation. However, only wild-type NME3 sustained ATP production and viability. Thus, the separate functions of NME3 in mitochondrial fusion and NDP kinase cooperate in metabolic adaptation for cell survival in response to glucose starvation. Given the critical role of mitochondrial dynamics and energy requirements in neuronal development, the homozygous mutation in NME3 is linked to a fatal mitochondrial neurodegenerative disorder.


Assuntos
Trifosfato de Adenosina , Metabolismo Energético/genética , Homozigoto , Dinâmica Mitocondrial/genética , Nucleosídeo NM23 Difosfato Quinases , Doenças Neurodegenerativas , Trifosfato de Adenosina/genética , Trifosfato de Adenosina/metabolismo , Linhagem Celular , Sobrevivência Celular , Feminino , Humanos , Masculino , Mitocôndrias/enzimologia , Mitocôndrias/genética , Mitocôndrias/patologia , Nucleosídeo NM23 Difosfato Quinases/genética , Nucleosídeo NM23 Difosfato Quinases/metabolismo , Doenças Neurodegenerativas/enzimologia , Doenças Neurodegenerativas/genética , Doenças Neurodegenerativas/patologia
10.
BMC Surg ; 22(1): 366, 2022 Oct 26.
Artigo em Inglês | MEDLINE | ID: mdl-36289500

RESUMO

BACKGROUND: Transforaminal Lumbar Interbody Fusion (TLIF) is commonly associated with higher complications and longer operative time. This study aims to evaluate the effectiveness, safety, and usability of a novel minimally invasive surgery (MIS) bone graft delivery device. METHODS: 73 consecutive patients with lumbar spondylosis, degenerative disc disease, spondylolisthesis, scoliosis or trauma were enrolled in this randomized controlled trial. Group 1 comprised 39 patients treated with the novel MIS bone graft delivery device. Group 2 consisted of 34 patients treated with the conventional system. The primary objective of the study was the assessment of the amount of bone graft delivery using the device. The secondary objectives were the effect of the device on operative time, pain relief, disability improvement, and bone fusion grade. RESULTS: Bone delivery amount was significantly higher in the MIS device group (6.7 ± 2.9 mL) compared to the conventional group (2.3 ± 0.5 mL), p < 0.001. Regarding the operation time, the MIS device group was associated significantly lower duration than the conventional group (p < 0.001). After a 3-month follow-up, 39.5% of the patients in the MIS device group and 3.5% of the patients in the conventional group were observed to achieve grade I fusion (complete fusion). There was a significant difference in fusion success rates (p < 0.01). CONCLUSION: The novel MIS bone graft delivery device was associated with successful bone delivery. Our MIS device provides promising modality with less operative time and higher bone fusion rates than conventional modalities. Trial Registration This trial was retrospectively registered on ClinicalTrials.gov (Registration date: 11/19/2021; Registration number: NCT05190055).


Assuntos
Fusão Vertebral , Espondilolistese , Humanos , Fusão Vertebral/métodos , Vértebras Lombares/cirurgia , Espondilolistese/cirurgia , Procedimentos Cirúrgicos Minimamente Invasivos/métodos , Duração da Cirurgia , Resultado do Tratamento , Estudos Retrospectivos
11.
Sensors (Basel) ; 22(9)2022 May 04.
Artigo em Inglês | MEDLINE | ID: mdl-35591180

RESUMO

The majority of digital sensors rely on von Neumann architecture microprocessors to process sampled data. When the sampled data require complex computation for 24×7, the processing element will a consume significant amount of energy and computation resources. Several new sensing algorithms use deep neural network algorithms and consume even more computation resources. High resource consumption prevents such systems for 24×7 deployment although they can deliver impressive results. This work adopts a Computing-In-Memory (CIM) device, which integrates a storage and analog processing unit to eliminate data movement, to process sampled data. This work designs and evaluates the CIM-based sensing framework for human pose recognition. The framework consists of uncertainty-aware training, activation function design, and CIM error model collection. The evaluation results show that the framework can improve the detection accuracy of three poses classification on CIM devices using binary weights from 33.3% to 91.5% while that on ideal CIM is 92.1%. Although on digital systems the accuracy is 98.7% with binary weight and 99.5% with floating weight, the energy consumption of executing 1 convolution layer on a CIM device is only 30,000 to 50,000 times less than the digital sensing system. Such a design can significantly reduce power consumption and enables battery-powered always-on sensors.


Assuntos
Algoritmos , Redes Neurais de Computação , Humanos
12.
RNA ; 25(5): 600-606, 2019 05.
Artigo em Inglês | MEDLINE | ID: mdl-30733327

RESUMO

The 70S ribosome is a major target for antibacterial drugs. Two of the classical antibiotics, chloramphenicol (CHL) and erythromycin (ERY), competitively bind to adjacent but separate sites on the bacterial ribosome: the catalytic peptidyl transferase center (PTC) and the nascent polypeptide exit tunnel (NPET), respectively. The previously reported competitive binding of CHL and ERY might be due either to a direct collision of the two drugs on the ribosome or due to a drug-induced allosteric effect. Because of the resolution limitations, the available structures of these antibiotics in complex with bacterial ribosomes do not allow us to discriminate between these two possible mechanisms. In this work, we have obtained two crystal structures of CHL and ERY in complex with the Thermus thermophilus 70S ribosome at a higher resolution (2.65 and 2.89 Å, respectively) allowing unambiguous placement of the drugs in the electron density maps. Our structures provide evidence of the direct collision of CHL and ERY on the ribosome, which rationalizes the observed competition between the two drugs.


Assuntos
Antibacterianos/química , Cloranfenicol/química , Eritromicina/química , Subunidades Ribossômicas/efeitos dos fármacos , Thermus thermophilus/efeitos dos fármacos , Antibacterianos/farmacologia , Sítios de Ligação , Ligação Competitiva , Cloranfenicol/farmacologia , Cristalografia por Raios X , Eritromicina/farmacologia , Escherichia coli/química , Escherichia coli/efeitos dos fármacos , Escherichia coli/genética , Escherichia coli/metabolismo , Modelos Moleculares , Peptidil Transferases/antagonistas & inibidores , Peptidil Transferases/química , Peptidil Transferases/genética , Peptidil Transferases/metabolismo , Ligação Proteica , Biossíntese de Proteínas , Conformação Proteica , Subunidades Ribossômicas/genética , Subunidades Ribossômicas/metabolismo , Subunidades Ribossômicas/ultraestrutura , Thermus thermophilus/química , Thermus thermophilus/genética , Thermus thermophilus/metabolismo
13.
J Antimicrob Chemother ; 76(5): 1205-1214, 2021 04 13.
Artigo em Inglês | MEDLINE | ID: mdl-33532826

RESUMO

OBJECTIVES: To investigate the in vitro activity of antibiotics against clinical Elizabethkingia anophelis isolates and to find a suitable antibiotic combination with synergistic effects to combat antibiotic-resistant E. anophelis and its associated biofilm. METHODS: E. anophelis isolates were identified by 16S rRNA sequencing; 30 strains with different pulsotypes were identified and the MIC, antibiotic resistance mechanism, antibiotic combination activity and killing effects of antimicrobial agents on biofilms of these strains were determined. RESULTS: All E. anophelis isolates were susceptible to minocycline and cefoperazone/sulbactam (1:1). More than 90% of clinical isolates were susceptible to cefoperazone/sulbactam (1:0.5), piperacillin/tazobactam and rifampicin. Some novel mutations, such as gyrA G81D, parE D585N and parC P134T, that have never been reported before, were identified. The synergistic effect was most prominent for the combination of minocycline and rifampicin, with 93.3% of their FIC index values ≤0.5, and no antagonism was observed using the chequerboard method. This synergistic effect between minocycline and rifampicin was also observed using time-killing methods for clinical E. anophelis isolates at both normal inoculum and high inoculum. Twenty-nine isolates tested positive for biofilm formation. Minocycline remained active against biofilm-embedded and biofilm-released planktonic E. anophelis cells; however, the enhanced effect of minocycline by adding rifampicin was only observed at 24 h (not at 72 and 120 h). CONCLUSIONS: Although E. anophelis was resistant to many antibiotics and could exhibit biofilm formation, minocycline showed potent in vitro activity against this pathogen and its associated biofilm.


Assuntos
Anti-Infecciosos , Plâncton , Antibacterianos/farmacologia , Biofilmes , Flavobacteriaceae , Testes de Sensibilidade Microbiana , RNA Ribossômico 16S/genética
14.
Ann Rheum Dis ; 80(8): 1048-1056, 2021 08.
Artigo em Inglês | MEDLINE | ID: mdl-33903093

RESUMO

OBJECTIVE: X-linked inhibitor of apoptosis protein (XIAP) is a multifunctional protein with important functions in apoptosis, cellular differentiation and cytoskeletal organisation and is emerging as potential target for the treatment of various cancers. The aim of the current study was to investigate the role of XIAP in the pathogenesis of systemic sclerosis (SSc). METHODS: The expression of XIAP in human skin samples of patients with SSc and chronic graft versus host disease (cGvHD) and healthy individuals was analysed by quantitative PCR, immunofluorescence (IF) and western blot. XIAP was inactivated by siRNA-mediated knockdown and pharmacological inhibition. The effects of XIAP inactivation were analysed in cultured fibroblasts and in the fibrosis models bleomycin-induced and topoisomerase-I-(topoI)-induced fibrosis and in Wnt10b-transgenic mice. RESULTS: The expression of XIAP, but not of other inhibitor of apoptosis protein family members, was increased in fibroblasts in SSc and sclerodermatous cGvHD. Transforming growth factor beta (TGF-ß) induced the expression of XIAP in a SMAD3-dependent manner. Inactivation of XIAP reduced WNT-induced fibroblast activation and collagen release. Inhibition of XIAP also ameliorated fibrosis induced by bleomycin, topoI and overexpression of Wnt10b in well-tolerated doses. The profibrotic effects of XIAP were mediated via WNT/ß-catenin signalling. Inactivation of XIAP reduces binding of ß-catenin to TCF to in a TLE-dependent manner to block WNT/ß-catenin-dependent transcription. CONCLUSIONS: Our data characterise XIAP as a novel link between two core pathways of fibrosis. XIAP is overexpressed in SSc and cGvHD in a TGF-ß/SMAD3-dependent manner and in turn amplifies the profibrotic effects of WNT/ß-catenin signalling on fibroblasts via transducin-like enhancer of split 3. Targeted inactivation of XIAP inhibits the aberrant activation of fibroblasts in murine models of SSc.


Assuntos
Escleroderma Sistêmico , Proteínas Inibidoras de Apoptose Ligadas ao Cromossomo X/metabolismo , beta Catenina , Animais , Bleomicina/farmacologia , Modelos Animais de Doenças , Fibroblastos/metabolismo , Fibrose , Humanos , Camundongos , Escleroderma Sistêmico/patologia , Pele/patologia , Fator de Crescimento Transformador beta/metabolismo , Proteínas Inibidoras de Apoptose Ligadas ao Cromossomo X/antagonistas & inibidores , beta Catenina/metabolismo
15.
Biol Lett ; 17(10): 20210388, 2021 10.
Artigo em Inglês | MEDLINE | ID: mdl-34610252

RESUMO

Anticipatory behaviour is the expectation of a near-future event based on information processed in the past and influences an animal's tactical decisions, particularly when there are significant fitness consequences. The grass lizard (Takydromus viridipunctatus) perches on blades of grass at night which likely reduces the probability of predation by terrestrial predators such as snakes, rodents and shrews. During twilight (starting 30 min before sunrise), they move from above the grass to within grass clumps and this is thought to afford the lizard protection while reducing detection by avian predators. Here, we examined how lizards shift their behaviour as a function of visual detectability to their primary predator, the cattle egret (Bubulcus ibis). We show that the lizards shift from their perch site during twilight at the earliest time at which egrets depart communal roosts. At the same time, visual modelling shows a dramatic increase in the detectability of the lizards to the visual system of egrets. Therefore, anticipatory behaviour in response to environmental cues acts to reduce predation risk as lizards become more conspicuous and predators become more active. Grass lizard anticipatory behaviour appears to be finely tuned by natural selection to adjust to temporal changes in predation risk.


Assuntos
Lagartos , Percas , Animais , Aves , Bovinos , Comportamento Predatório , Serpentes
16.
Int J Mol Sci ; 22(7)2021 Apr 06.
Artigo em Inglês | MEDLINE | ID: mdl-33917452

RESUMO

Due to the increasing incidence of malignant gliomas, particularly glioblastoma multiforme (GBM), a simple and reliable GBM diagnosis is needed to screen early the death-threaten patients. This study aimed to identify a protein that can be used to discriminate GBM from low-grade astrocytoma and elucidate further that it has a functional role during malignant glioma progressions. To identify proteins that display low or no expression in low-grade astrocytoma but elevated levels in GBM, glycoprotein fibronectin (FN) was particularly examined according to the mining of the Human Protein Atlas. Web-based open megadata minings revealed that FN was mainly mutated in the cBio Cancer Genomic Portal but dominantly overexpressed in the ONCOMINE (a cancer microarray database and integrated data-mining platform) in distinct tumor types. Furthermore, numerous different cancer patients with high FN indeed exhibited a poor prognosis in the PrognoScan mining, indicating that FN involves in tumor malignancy. To investigate further the significance of FN expression in glioma progression, tumor specimens from five malignant gliomas with recurrences that received at least two surgeries were enrolled and examined. The immunohistochemical staining showed that FN expression indeed determined the distinct progressions of malignant gliomas. Furthermore, the expression of vimentin (VIM), a mesenchymal protein that is strongly expressed in malignant cancers, was similar to the FN pattern. Moreover, the level of epithelial-mesenchymal transition (EMT) inducer transforming growth factor-beta (TGF-ß) was almost recapitulated with the FN expression. Together, this study identifies a protein FN that can be used to diagnose GBM from low-grade astrocytoma; moreover, its expression functionally determines the malignant glioma progressions via TGF-ß-induced EMT pathway.


Assuntos
Neoplasias Encefálicas/metabolismo , Fibronectinas/biossíntese , Regulação Neoplásica da Expressão Gênica , Glioblastoma/metabolismo , Proteínas de Neoplasias/biossíntese , Transdução de Sinais , Fator de Crescimento Transformador beta/metabolismo , Adulto , Neoplasias Encefálicas/diagnóstico , Neoplasias Encefálicas/diagnóstico por imagem , Neoplasias Encefálicas/genética , Bases de Dados de Ácidos Nucleicos , Feminino , Fibronectinas/genética , Glioblastoma/diagnóstico , Glioblastoma/diagnóstico por imagem , Glioblastoma/genética , Humanos , Masculino , Pessoa de Meia-Idade , Proteínas de Neoplasias/genética , Prognóstico , Fator de Crescimento Transformador beta/genética
17.
J Biomed Inform ; 107: 103438, 2020 07.
Artigo em Inglês | MEDLINE | ID: mdl-32360937

RESUMO

Identifying patients eligible for clinical trials using electronic health records (EHRs) is a challenging task usually requiring a comprehensive analysis of information stored in multiple EHRs of a patient. The goal of this study is to investigate different methods and their effectiveness in identifying patients that meet specific eligibility selection criteria based on patients' longitudinal records. An unstructured dataset released by the n2c2 cohort selection for clinical trials track was used, each of which included 2-5 records manually annotated to thirteen pre-defined selection criteria. Unlike the other studies, we formulated the problem as a multiple instance learning (MIL) task and compared the performance with that of the rule-based and the single instance-based classifiers. Our official best run achieved an average micro-F score of 0.8765 which was ranked as one of the top ten results in the track. Further experiments demonstrated that the performance of the MIL-based classifiers consistently yield better performance than their single-instance counterparts in the criteria that require the overall comprehension of the information distributed among all of the patient's EHRs. Rule-based and single instance learning approaches exhibited better performance in criteria that don't require a consideration of several factors across records. This study demonstrated that cohort selection using longitudinal patient records can be formulated as a MIL problem. Our results exhibit that the MIL-based classifiers supplement the rule-based methods and provide better results in comparison to the single instance learning approaches.


Assuntos
Registros Eletrônicos de Saúde , Aprendizado de Máquina , Estudos de Coortes , Humanos , Motivação , Seleção de Pacientes
18.
Int J Mol Sci ; 21(14)2020 Jul 17.
Artigo em Inglês | MEDLINE | ID: mdl-32708927

RESUMO

NME3 is a member of the nucleoside diphosphate kinase (NDPK) family that binds to the mitochondrial outer membrane to stimulate mitochondrial fusion. In this study, we showed that NME3 knockdown delayed DNA repair without reducing the cellular levels of nucleotide triphosphates. Further analyses revealed that NME3 knockdown increased fragmentation of mitochondria, which in turn led to mitochondrial oxidative stress-mediated DNA single-strand breaks (SSBs) in nuclear DNA. Re-expression of wild-type NME3 or inhibition of mitochondrial fission markedly reduced SSBs and facilitated DNA repair in NME3 knockdown cells, while expression of N-terminal deleted mutant defective in mitochondrial binding had no rescue effect. We further showed that disruption of mitochondrial fusion by knockdown of NME4 or MFN1 also caused mitochondrial oxidative stress-mediated genome instability. In conclusion, the contribution of NME3 to redox-regulated genome stability lies in its function in mitochondrial fusion.


Assuntos
Dano ao DNA , Mitocôndrias/metabolismo , Nucleosídeo NM23 Difosfato Quinases/metabolismo , Estresse Oxidativo , Espécies Reativas de Oxigênio/metabolismo , Técnicas de Silenciamento de Genes , Instabilidade Genômica , Células HEK293 , Células HeLa , Humanos , Mitocôndrias/genética , Nucleosídeo NM23 Difosfato Quinases/genética
19.
Acta Cardiol Sin ; 36(6): 595-602, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-33235415

RESUMO

BACKGROUND: Risk score is widely used in non-ST segment elevation myocardial infarction (NSTEMI) patients to predict the in-hospital outcome for immediate coronary angiography decision and care of unit selection. OBJECTIVES: This study compared the performances of the thrombolysis in myocardial infarction (TIMI), Global Registry of Acute Coronary Events (GRACE), Primary Angioplasty in Myocardial Infarction (PAMI), and Revised Controlled Abciximab and Device Investigation to Lower Late Angioplasty Complications (Revised CADILLAC) risk scores in predicting in-hospital and long-term outcomes in diabetic NSTEMI patients. METHODS: A total of 750 diabetic NSTEMI patients from 27 hospitals were enrolled between January 2013 and December 2015 in the nationwide registry initiated by the Taiwan Society of Cardiology. Four score systems were calculated with receiver operator characteristic analysis used to compare outcome discrimination performance. RESULTS: No studied risk scores reached acceptable discrimination per area under curve (AUC) in the prediction of in-hospital outcome except for the revised CADILLAC score which reached acceptable discrimination in new-onset cardiogenic shock (AUC = 0.7191) and acute renal failure (AUC = 0.7283). In long-term outcomes, only the revised CADILLAC score reached acceptable discrimination of mortality prediction at 6, 12 and 24 months (AUC = 0.7261 at 6 months, 0.7319 at 12 months, and 0.7256 at 24 months). Subgroup analysis based on the revised CADILLAC score risk class showed a significant difference in adjusted mortality rate between low-risk group/intermediate-risk group and high-risk group. CONCLUSIONS: Only the revised CADILLAC score showed acceptable accuracy to predict the long-term mortality outcome among the scores studied.

20.
J Neurosci Res ; 97(2): 185-201, 2019 02.
Artigo em Inglês | MEDLINE | ID: mdl-30311677

RESUMO

Bidirectional cargo transport in neurons can be explained by two models: the "tug-of-war model" for short-range transport, in which several kinesin and dynein motors are bound to the same cargo but travel in opposing directions, and by the "motor coordination model" for long-range transport, in which small adaptors or the cargo itself activates or deactivates opposing motors. Direct interactions between the major axonal transporter kinesin-3 UNC-104(KIF1A) and the dynein/dynactin complex remains unknown. In this study, we dissected and evaluated the interaction sites between UNC-104 and dynein as well as between UNC-104 and dynactin using yeast two-hybrid assays. We found that the DYLT-1(Tctex) subunit of dynein binds near the coiled coil 3 (CC3) of UNC-104, and that the DYRB-1(Roadblock) subunit binds near the CC2 region of UNC-104. Regarding dynactin, we specifically revealed strong interactions between DNC-6(p27) and the FHA-CC3 stretch of UNC-104, as well as between the DNC-5(p25) and the CC2-CC3 region of UNC-104. Motility analysis of motors and cargo in the nervous system of Caenorhabditis elegans revealed impaired transport of UNC-104 and synaptic vesicles in dynein and dynactin mutants (or in RNAi knockdown animals). Further, in these mutants UNC-104 clustering along axons was diminished. Interestingly, when dynamic UNC-104 motors enter a stationary UNC-104 cluster their dwelling times are increased in dynein mutants (suggesting that dynein may act as an UNC-104 activator). In summary, we provide novel insights on how UNC-104 interacts with the dynein/dynactin complex and how UNC-104 driven axonal transport depends on dynein/dynactin in C. elegans neurons.


Assuntos
Transporte Axonal/fisiologia , Proteínas de Caenorhabditis elegans/fisiologia , Complexo Dinactina/fisiologia , Dineínas/fisiologia , Proteínas do Tecido Nervoso/fisiologia , Domínios e Motivos de Interação entre Proteínas/fisiologia , Animais , Transporte Axonal/genética , Axônios/metabolismo , Caenorhabditis elegans , Proteínas de Caenorhabditis elegans/metabolismo , Ensaios de Migração Celular , Complexo Dinactina/genética , Dineínas/genética , Cinesinas , Proteínas Associadas aos Microtúbulos , Proteínas do Tecido Nervoso/metabolismo , Neurônios/metabolismo , Vesículas Sinápticas/metabolismo
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