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1.
Cell ; 173(7): 1650-1662.e14, 2018 06 14.
Artigo em Inglês | MEDLINE | ID: mdl-29887376

RESUMO

NusG/RfaH/Spt5 transcription elongation factors are the only transcription regulators conserved across all life. Bacterial NusG regulates RNA polymerase (RNAP) elongation complexes (ECs) across most genes, enhancing elongation by suppressing RNAP backtracking and coordinating ρ-dependent termination and translation. The NusG paralog RfaH engages the EC only at operon polarity suppressor (ops) sites and suppresses both backtrack and hairpin-stabilized pausing. We used single-particle cryoelectron microscopy (cryo-EM) to determine structures of ECs at ops with NusG or RfaH. Both factors chaperone base-pairing of the upstream duplex DNA to suppress backtracking, explaining stimulation of elongation genome-wide. The RfaH-opsEC structure reveals how RfaH confers operon specificity through specific recognition of an ops hairpin in the single-stranded nontemplate DNA and tighter binding to the EC to exclude NusG. Tight EC binding by RfaH sterically blocks the swiveled RNAP conformation necessary for hairpin-stabilized pausing. The universal conservation of NusG/RfaH/Spt5 suggests that the molecular mechanisms uncovered here are widespread.


Assuntos
Proteínas de Escherichia coli/metabolismo , Fatores de Alongamento de Peptídeos/metabolismo , Fatores de Transcrição/metabolismo , Transcrição Gênica , Sequência de Aminoácidos , Domínio Catalítico , Microscopia Crioeletrônica , DNA/química , DNA/metabolismo , RNA Polimerases Dirigidas por DNA/química , RNA Polimerases Dirigidas por DNA/genética , RNA Polimerases Dirigidas por DNA/metabolismo , Escherichia coli/metabolismo , Proteínas de Escherichia coli/química , Proteínas de Escherichia coli/genética , Conformação de Ácido Nucleico , Fatores de Alongamento de Peptídeos/química , Fatores de Alongamento de Peptídeos/genética , Ligação Proteica , Estrutura Quaternária de Proteína , Proteínas Recombinantes/biossíntese , Proteínas Recombinantes/química , Proteínas Recombinantes/isolamento & purificação , Alinhamento de Sequência , Transativadores/química , Transativadores/genética , Transativadores/metabolismo , Fatores de Transcrição/química , Fatores de Transcrição/genética , Óperon de RNAr/genética
2.
Cell ; 173(2): 371-385.e18, 2018 04 05.
Artigo em Inglês | MEDLINE | ID: mdl-29625053

RESUMO

Identifying molecular cancer drivers is critical for precision oncology. Multiple advanced algorithms to identify drivers now exist, but systematic attempts to combine and optimize them on large datasets are few. We report a PanCancer and PanSoftware analysis spanning 9,423 tumor exomes (comprising all 33 of The Cancer Genome Atlas projects) and using 26 computational tools to catalog driver genes and mutations. We identify 299 driver genes with implications regarding their anatomical sites and cancer/cell types. Sequence- and structure-based analyses identified >3,400 putative missense driver mutations supported by multiple lines of evidence. Experimental validation confirmed 60%-85% of predicted mutations as likely drivers. We found that >300 MSI tumors are associated with high PD-1/PD-L1, and 57% of tumors analyzed harbor putative clinically actionable events. Our study represents the most comprehensive discovery of cancer genes and mutations to date and will serve as a blueprint for future biological and clinical endeavors.


Assuntos
Neoplasias/patologia , Algoritmos , Antígeno B7-H1/genética , Biologia Computacional , Bases de Dados Genéticas , Entropia , Humanos , Instabilidade de Microssatélites , Mutação , Neoplasias/genética , Neoplasias/imunologia , Análise de Componente Principal , Receptor de Morte Celular Programada 1/genética
4.
Nature ; 610(7931): 356-365, 2022 10.
Artigo em Inglês | MEDLINE | ID: mdl-36198802

RESUMO

Hepatocellular carcinoma (HCC), the fourth leading cause of cancer mortality worldwide, develops almost exclusively in patients with chronic liver disease and advanced fibrosis1,2. Here we interrogated functions of hepatic stellate cells (HSCs), the main source of liver fibroblasts3, during hepatocarcinogenesis. Genetic depletion, activation or inhibition of HSCs in mouse models of HCC revealed their overall tumour-promoting role. HSCs were enriched in the preneoplastic environment, where they closely interacted with hepatocytes and modulated hepatocarcinogenesis by regulating hepatocyte proliferation and death. Analyses of mouse and human HSC subpopulations by single-cell RNA sequencing together with genetic ablation of subpopulation-enriched mediators revealed dual functions of HSCs in hepatocarcinogenesis. Hepatocyte growth factor, enriched in quiescent and cytokine-producing HSCs, protected against hepatocyte death and HCC development. By contrast, type I collagen, enriched in activated myofibroblastic HSCs, promoted proliferation and tumour development through increased stiffness and TAZ activation in pretumoural hepatocytes and through activation of discoidin domain receptor 1 in established tumours. An increased HSC imbalance between cytokine-producing HSCs and myofibroblastic HSCs during liver disease progression was associated with increased HCC risk in patients. In summary, the dynamic shift in HSC subpopulations and their mediators during chronic liver disease is associated with a switch from HCC protection to HCC promotion.


Assuntos
Carcinogênese , Carcinoma Hepatocelular , Células Estreladas do Fígado , Neoplasias Hepáticas , Animais , Carcinogênese/patologia , Carcinoma Hepatocelular/patologia , Proliferação de Células , Colágeno Tipo I/metabolismo , Receptor com Domínio Discoidina 1/metabolismo , Progressão da Doença , Células Estreladas do Fígado/metabolismo , Células Estreladas do Fígado/patologia , Fator de Crescimento de Hepatócito/metabolismo , Hepatócitos , Humanos , Cirrose Hepática/complicações , Neoplasias Hepáticas/patologia , Camundongos , Miofibroblastos/patologia
5.
Annu Rev Biochem ; 80: 917-41, 2011.
Artigo em Inglês | MEDLINE | ID: mdl-21548780

RESUMO

Innate immune receptors respond to common structural patterns in microbial molecules and are called pattern recognition receptors. Toll-like receptors (TLRs) play critical roles in the innate immune system by recognizing microbial lipids, carbohydrates, nucleic acids, and proteins. Precise definition of the ligand "pattern" of TLRs has been difficult to determine primarily owing to a lack of high-resolution structures. Recently, the structures of several TLR-ligand complexes and the intracellular signaling domains have been determined by X-ray crystallography. This new structural information, combined with extensive biochemical and immunological data accumulated over decades, sheds new light on ligand-recognition and -activation mechanisms. In this review, we summarize the TLR structures and discuss proposed ligand-recognition and -activation mechanisms.


Assuntos
Conformação Proteica , Receptores Toll-Like/química , Animais , Sítios de Ligação , Cristalografia por Raios X , Humanos , Imunidade Inata , Ligantes , Lipopolissacarídeos/imunologia , Antígeno 96 de Linfócito/química , Antígeno 96 de Linfócito/genética , Antígeno 96 de Linfócito/imunologia , Modelos Moleculares , Filogenia , Multimerização Proteica , Receptores Toll-Like/classificação , Receptores Toll-Like/genética , Receptores Toll-Like/imunologia
6.
Mol Cell ; 69(5): 802-815.e5, 2018 03 01.
Artigo em Inglês | MEDLINE | ID: mdl-29499135

RESUMO

Sequence-specific pausing by RNA polymerase (RNAP) during transcription plays crucial and diverse roles in gene expression. In bacteria, RNA structures are thought to fold within the RNA exit channel of the RNAP and can increase pause lifetimes significantly. The biophysical mechanism of pausing is uncertain. We used single-particle cryo-EM to determine structures of paused complexes, including a 3.8-Å structure of an RNA hairpin-stabilized, paused RNAP that coordinates RNA folding in the his operon attenuation control region of E. coli. The structures revealed a half-translocated pause state (RNA post-translocated, DNA pre-translocated) that can explain transcriptional pausing and a global conformational change of RNAP that allosterically inhibits trigger loop folding and can explain pause hairpin action. Pause hairpin interactions with the RNAP RNA exit channel suggest how RNAP guides the formation of nascent RNA structures.


Assuntos
RNA Polimerases Dirigidas por DNA/química , Proteínas de Escherichia coli/química , Escherichia coli/química , Dobramento de RNA , RNA Bacteriano/química , Transcrição Gênica , Regulação Alostérica , RNA Polimerases Dirigidas por DNA/genética , RNA Polimerases Dirigidas por DNA/metabolismo , Escherichia coli/genética , Escherichia coli/metabolismo , Proteínas de Escherichia coli/genética , Proteínas de Escherichia coli/metabolismo , Domínios Proteicos , RNA Bacteriano/genética , RNA Bacteriano/metabolismo
7.
Proc Natl Acad Sci U S A ; 120(8): e2215945120, 2023 02 21.
Artigo em Inglês | MEDLINE | ID: mdl-36795753

RESUMO

Transcriptional pausing underpins the regulation of cellular RNA synthesis, but its mechanism remains incompletely understood. Sequence-specific interactions of DNA and RNA with the dynamic, multidomain RNA polymerase (RNAP) trigger reversible conformational changes at pause sites that temporarily interrupt the nucleotide addition cycle. These interactions initially rearrange the elongation complex (EC) into an elemental paused EC (ePEC). ePECs can form longer-lived PECs by further rearrangements or interactions of diffusible regulators. For both bacterial and mammalian RNAPs, a half-translocated state in which the next DNA template base fails to load into the active site appears central to the ePEC. Some RNAPs also swivel interconnected modules that may stabilize the ePEC. However, it is unclear whether swiveling and half-translocation are requisite features of a single ePEC state or if multiple ePEC states exist. Here, we use cryo-electron microscopy (cryo-EM) analysis of ePECs with different RNA-DNA sequences combined with biochemical probes of ePEC structure to define an interconverting ensemble of ePEC states. ePECs occupy either pre- or half-translocated states but do not always swivel, indicating that difficulty in forming the posttranslocated state at certain RNA-DNA sequences may be the essence of the ePEC. The existence of multiple ePEC conformations has broad implications for transcriptional regulation.


Assuntos
RNA Polimerases Dirigidas por DNA , RNA , Microscopia Crioeletrônica , RNA Polimerases Dirigidas por DNA/metabolismo , RNA/genética , DNA , Nucleotídeos/química , Transcrição Gênica
8.
Cell Mol Life Sci ; 81(1): 155, 2024 Mar 28.
Artigo em Inglês | MEDLINE | ID: mdl-38538986

RESUMO

The prostate is a vital accessory gonad in the mammalian male reproductive system. With the ever-increasing proportion of the population over 60 years of age worldwide, the incidence of prostate diseases, such as benign prostatic hyperplasia (BPH) and prostate cancer (PCa), is on the rise and is gradually becoming a significant medical problem globally. The notch signaling pathway is essential in regulating prostate early development. However, the potential regulatory mechanism of Notch signaling in prostatic enlargement and hyperplasia remains unclear. In this study, we proved that overactivation of Notch1 signaling in mouse prostatic epithelial cells (OEx) led to prostatic enlargement via enhancing proliferation and inhibiting apoptosis of prostatic epithelial cells. Further study showed that N1ICD/RBPJ directly up-regulated the androgen receptor (AR) and enhanced prostatic sensitivity to androgens. Hyper-proliferation was not found in orchidectomized OEx mice without androgen supply but was observed after Dihydrotestosterone (DHT) supplementation. Our data showed that the number of mitochondrion in prostatic epithelial cells of OEx mice was increased, but the mitochondrial function was impaired, and the essential activity of the mitochondrial respiratory electron transport chain was significantly weakened. Disordered mitochondrial number and metabolic function further resulted in excessive accumulation of reactive oxygen species (ROS). Importantly, anti-oxidant N-Acetyl-L-Cysteine (NAC) therapy could alleviate prostatic hyperplasia caused by the over-activation of Notch1 signaling. Furthermore, we observed the incremental Notch signaling activity in progenitor-like club cells in the scRNA-seq data set of human BPH patients. Moreover, the increased number of TROP2+ progenitors and Club cells was also confirmed in our OEx mice. In conclusion, our study revealed that over-activated Notch1 signaling induces prostatic enlargement by increasing androgen receptor sensitivity, disrupting cellular mitochondrial metabolism, increasing ROS, and a higher number of progenitor cells, all of which can be effectively rescued by NAC treatment.


Assuntos
Hiperplasia Prostática , Animais , Humanos , Masculino , Camundongos , Androgênios/metabolismo , Mamíferos/metabolismo , Mitocôndrias/metabolismo , Próstata/metabolismo , Hiperplasia Prostática/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Receptores Androgênicos/genética , Receptores Androgênicos/metabolismo , Transdução de Sinais
9.
Nucleic Acids Res ; 51(18): 9838-9848, 2023 Oct 13.
Artigo em Inglês | MEDLINE | ID: mdl-37638763

RESUMO

The R-loops forming around DNA double-strand breaks (DSBs) within actively transcribed genes play a critical role in the DSB repair process. However, the mechanisms underlying R-loop formation at DSBs remain poorly understood, with diverse proposed models involving protein factors associated with RNA polymerase (RNAP) loading, pausing/backtracking or preexisting transcript RNA invasion. In this single-molecule study using Escherichia coli RNAP, we discovered that transcribing RNAP alone acts as a highly effective DSB sensor, responsible for generation of R-loops upon encountering downstream DSBs, without requiring any additional factors. The R-loop formation efficiency is greatly influenced by DNA end structures, ranging here from 2.8% to 73%, and notably higher on sticky ends with 3' or 5' single-stranded overhangs compared to blunt ends without any overhangs. The R-loops extend unidirectionally upstream from the DSB sites and can reach the transcription start site, interfering with ongoing-round transcription. Furthermore, the extended R-loops can persist and maintain their structures, effectively preventing the efficient initiation of subsequent transcription rounds. Our results are consistent with the bubble extension model rather than the 5'-end invasion model or the middle insertion model. These discoveries provide valuable insights into the initiation of DSB repair on transcription templates across bacteria, archaea and eukaryotes.

10.
Nucleic Acids Res ; 51(6): 2778-2789, 2023 04 11.
Artigo em Inglês | MEDLINE | ID: mdl-36762473

RESUMO

Transcriptional pause is essential for all types of termination. In this single-molecule study on bacterial Rho factor-dependent terminators, we confirm that the three Rho-dependent termination routes operate compatibly together in a single terminator, and discover that their termination efficiencies depend on the terminational pauses in unexpected ways. Evidently, the most abundant route is that Rho binds nascent RNA first and catches up with paused RNA polymerase (RNAP) and this catch-up Rho mediates simultaneous releases of transcript RNA and template DNA from RNAP. The fastest route is that the catch-up Rho effects RNA-only release and leads to 1D recycling of RNAP on DNA. The slowest route is that the RNAP-prebound stand-by Rho facilitates only the simultaneous rather than sequential releases. Among the three routes, only the stand-by Rho's termination efficiency positively correlates with pause duration, contrary to a long-standing speculation, invariably in the absence or presence of NusA/NusG factors, competitor RNAs or a crowding agent. Accordingly, the essential terminational pause does not need to be long for the catch-up Rho's terminations, and long pauses benefit only the stand-by Rho's terminations. Furthermore, the Rho-dependent termination of mgtA and ribB riboswitches is controlled mainly by modulation of the stand-by rather than catch-up termination.


Assuntos
Proteínas de Escherichia coli , Fator Rho , Terminação da Transcrição Genética , RNA Polimerases Dirigidas por DNA/metabolismo , Proteínas de Escherichia coli/genética , Fator Rho/genética , Fator Rho/metabolismo , Riboswitch , Transcrição Gênica
11.
Gastroenterology ; 164(3): 439-453, 2023 03.
Artigo em Inglês | MEDLINE | ID: mdl-36402191

RESUMO

BACKGROUND & AIMS: Obesity predisposes to type 2 diabetes (T2D) and nonalcoholic fatty liver disease (NAFLD), but underlying mechanisms are incompletely understood. Potassium channel tetramerization domain-containing protein 17 (Kctd17) levels are increased in livers from obese mice and humans. In this study, we investigated the mechanism of increased Kctd17 and whether it is causal to obesity-induced metabolic complications. METHODS: We transduced Rosa26-LSL-Cas9 knockin mice with AAV8-TBG-Cre (Control), AAV8-U6-Kctd17 sgRNA-TBG-Cre (L-Kctd17), AAV8-U6-Oga sgRNA-TBG-Cre (L-Oga), or AAV8-U6-Kctd17/Oga sgRNA-TBG-Cre (DKO). We fed mice a high-fat diet (HFD) and assessed for hepatic glucose and lipid homeostasis. We generated Kctd17, O-GlcNAcase (Oga), or Kctd17/Oga-knockout hepatoma cells by CRISPR-Cas9, and Kctd17-directed antisense oligonucleotide to test therapeutic potential in vivo. We analyzed transcriptomic data from patients with NAFLD. RESULTS: Hepatocyte Kctd17 expression was increased in HFD-fed mice due to increased Srebp1c activity. HFD-fed L-Kctd17 or Kctd17 antisense oligonucleotide-treated mice show improved glucose tolerance and hepatic steatosis, whereas forced Kctd17 expression caused glucose intolerance and hepatic steatosis even in lean mice. Kctd17 induced Oga degradation, resulting in increasing carbohydrate response element-binding protein (Chrebp) protein, so concomitant Oga knockout negated metabolic benefits of hepatocyte Kctd17 deletion. In patients with NAFLD, KCTD17 messenger RNA was positively correlated with expression of Chrebp target and other lipogenic genes. CONCLUSIONS: Srebp1c-induced hepatocyte Kctd17 expression in obesity disrupted glucose and lipid metabolism by stabilizing Chrebp, and may represent a novel therapeutic target for obesity-induced T2D and NAFLD.


Assuntos
Diabetes Mellitus Tipo 2 , Intolerância à Glucose , Resistência à Insulina , Hepatopatia Gordurosa não Alcoólica , Humanos , Animais , Camundongos , Hepatopatia Gordurosa não Alcoólica/metabolismo , Diabetes Mellitus Tipo 2/complicações , Resistência à Insulina/fisiologia , Fatores de Transcrição/genética , Fígado/metabolismo , Hepatócitos/metabolismo , Obesidade/complicações , Glucose/metabolismo , Dieta Hiperlipídica , Camundongos Endogâmicos C57BL , Proteínas Adaptadoras de Transdução de Sinal/metabolismo
12.
Crit Care Med ; 52(3): 483-494, 2024 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-37921532

RESUMO

OBJECTIVES: Extracorporeal cardiopulmonary resuscitation (ECPR) serves as a lifesaving intervention for patients experiencing refractory cardiac arrest. With its expanding usage, there is a burgeoning focus on improving patient outcomes through optimal management in the acute phase after cannulation. This review explores systematic post-cardiac arrest management strategies, associated complications, and prognostication in ECPR patients. DATA SOURCES: A PubMed search from inception to 2023 using search terms such as post-cardiac arrest care, ICU management, prognostication, and outcomes in adult ECPR patients was conducted. STUDY SELECTION: Selection includes original research, review articles, and guidelines. DATA EXTRACTION: Information from relevant publications was reviewed, consolidated, and formulated into a narrative review. DATA SYNTHESIS: We found limited data and no established clinical guidelines for post-cardiac arrest care after ECPR. In contrast to non-ECPR patients where systematic post-cardiac arrest care is shown to improve the outcomes, there is no high-quality data on this topic after ECPR. This review outlines a systematic approach, albeit limited, for ECPR care, focusing on airway/breathing and circulation as well as critical aspects of ICU care, including analgesia/sedation, mechanical ventilation, early oxygen/C o2 , and temperature goals, nutrition, fluid, imaging, and neuromonitoring strategy. We summarize common on-extracorporeal membrane oxygenation complications and the complex nature of prognostication and withdrawal of life-sustaining therapy in ECPR. Given conflicting outcomes in ECPR randomized controlled trials focused on pre-cannulation care, a better understanding of hemodynamic, neurologic, and metabolic abnormalities and early management goals may be necessary to improve their outcomes. CONCLUSIONS: Effective post-cardiac arrest care during the acute phase of ECPR is paramount in optimizing patient outcomes. However, a dearth of evidence to guide specific management strategies remains, indicating the necessity for future research in this field.


Assuntos
Reanimação Cardiopulmonar , Oxigenação por Membrana Extracorpórea , Parada Cardíaca , Parada Cardíaca Extra-Hospitalar , Adulto , Humanos , Parada Cardíaca/terapia , Parada Cardíaca/etiologia , Reanimação Cardiopulmonar/métodos , Respiração Artificial , Oxigenação por Membrana Extracorpórea/métodos , Parada Cardíaca Extra-Hospitalar/terapia , Estudos Retrospectivos
13.
FASEB J ; 37(4): e22870, 2023 04.
Artigo em Inglês | MEDLINE | ID: mdl-36929052

RESUMO

Enhancers activate gene transcription remotely, which requires tissue specific transcription factors binding to them. GATA1 and TAL1 are hematopoietic/erythroid-specific factors and often bind together to enhancers, activating target genes. Interestingly, we found that some hematopoietic/erythroid genes are transcribed in a GATA1-dependent but TAL1-independnet manner. They appear to have enhancers within a relatively short distance. In this study, we paired highly transcribed hematopoietic/erythroid genes with the nearest GATA1/TAL1-binding enhancers and analyzed these putative enhancer-gene pairs depending on distance between them. Enhancers located at various distances from genes in the pairs, which was not related to transcription level of the genes. However, genes with enhancers at short distances away tended to be transcriptionally unaffected by TAL1 depletion. Histone H3K27ac extended from the enhancers to target genes. The H3K27ac extension was maintained without TAL1, even though it disappeared owing to the loss of GATA1. Intergenic RNA was highly transcribed from the enhancers to nearby target genes, independent of TAL1. Taken together, TAL1-independent transcription of hematopoietic/erythroid genes appears to be promoted by enhancers present in a short distance. These enhancers are likely to activate nearby target genes by tracking the intervening regions.


Assuntos
DNA Intergênico , Elementos Facilitadores Genéticos , Hematopoese , Histonas , DNA Intergênico/genética , DNA Intergênico/metabolismo , Hematopoese/genética , Histonas/genética , Histonas/metabolismo , Proteínas Proto-Oncogênicas/genética , Proteínas Proto-Oncogênicas/metabolismo , RNA/metabolismo , Proteína 1 de Leucemia Linfocítica Aguda de Células T/genética , Proteína 1 de Leucemia Linfocítica Aguda de Células T/metabolismo
14.
FASEB J ; 37(7): e22983, 2023 07.
Artigo em Inglês | MEDLINE | ID: mdl-37249327

RESUMO

In mammals, the endometrium undergoes dynamic changes in response to estrogen and progesterone to prepare for blastocyst implantation. Two distinct types of endometrial epithelial cells, the luminal (LE) and glandular (GE) epithelial cells play different functional roles during this physiological process. Previously, we have reported that Notch signaling plays multiple roles in embryo implantation, decidualization, and postpartum repair. Here, using the uterine epithelial-specific Ltf-iCre, we showed that Notch1 signaling over-activation in the endometrial epithelium caused dysfunction of the epithelium during the estrous cycle, resulting in hyper-proliferation. During pregnancy, it further led to dysregulation of estrogen and progesterone signaling, resulting in infertility in these animals. Using 3D organoids, we showed that over-activation of Notch1 signaling increased the proliferative potential of both LE and GE cells and reduced the difference in transcription profiles between them, suggesting disrupted differentiation of the uterine epithelium. In addition, we demonstrated that both canonical and non-canonical Notch signaling contributed to the hyper-proliferation of GE cells, but only the non-canonical pathway was involved with estrogen sensitivity in the GE cells. These findings provided insights into the effects of Notch1 signaling on the proliferation, differentiation, and function of the uterine epithelium. This study demonstrated the important roles of Notch1 signaling in regulating hormone response and differentiation of endometrial epithelial cells and provides an opportunity for future studies in estrogen-dependent diseases, such as endometriosis.


Assuntos
Progesterona , Útero , Animais , Feminino , Camundongos , Gravidez , Proliferação de Células , Implantação do Embrião/fisiologia , Endométrio/metabolismo , Epitélio/metabolismo , Estrogênios/farmacologia , Estrogênios/metabolismo , Progesterona/farmacologia , Progesterona/metabolismo , Útero/metabolismo
15.
J Surg Res ; 299: 290-297, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38788465

RESUMO

INTRODUCTION: More than 1.2 million pulmonary artery catheters (PACs) are used in cardiac patients per annum within the United States. However, it is contraindicated in traditional 1.5 and 3T magnetic resonance imaging (MRI) scans. We aimed to test preclinical and clinical safety of using this imaging modality given the potential utility of needing it in the clinical setting. METHODS: We conducted two phantom experiments to ensure that the electromagnetic field power deposition associated with bare and jacketed PACs was safe and within the acceptable limit established by the Food and Drug Administration. The primary end points were the safety and feasibility of performing Point-of-Care (POC) MRI without imaging-related adverse events. We performed a preclinical computational electromagnetic simulation and evaluated these findings in nine patients with PACs on veno-arterial extracorporeal membrane oxygenation. RESULTS: The phantom experiments showed that the baseline point specific absorption rate through the head averaged 0.4 W/kg. In both the bare and jacketed catheters, the highest net specific absorption rates were at the neck entry point and tip but were negligible and unlikely to cause any heat-related tissue or catheter damage. In nine patients (median age 66, interquartile range 42-72 y) with veno-arterial extracorporeal membrane oxygenation due to cardiogenic shock and PACs placed for close hemodynamic monitoring, POC MRI was safe and feasible with good diagnostic imaging quality. CONCLUSIONS: Adult ECMO patients with PACs can safely undergo point-of-care low-field (64 mT) brain MRI within a reasonable timeframe in an intensive care unit setting to assess for acute brain injury that might otherwise be missed with conventional head computed tomography.


Assuntos
Encéfalo , Cateterismo de Swan-Ganz , Oxigenação por Membrana Extracorpórea , Imageamento por Ressonância Magnética , Imagens de Fantasmas , Sistemas Automatizados de Assistência Junto ao Leito , Humanos , Masculino , Pessoa de Meia-Idade , Imageamento por Ressonância Magnética/efeitos adversos , Imageamento por Ressonância Magnética/métodos , Feminino , Oxigenação por Membrana Extracorpórea/instrumentação , Oxigenação por Membrana Extracorpórea/efeitos adversos , Oxigenação por Membrana Extracorpórea/métodos , Idoso , Adulto , Encéfalo/diagnóstico por imagem , Cateterismo de Swan-Ganz/instrumentação , Cateterismo de Swan-Ganz/efeitos adversos , Estudos de Viabilidade
16.
Headache ; 64(2): 149-155, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38284247

RESUMO

OBJECTIVE: To evaluate the efficacy of prednisolone in the treatment of medication-overuse headache (MOH) using data from a multicenter prospective registry (Registry for Load and Management of Medication Overuse Headache [RELEASE]). BACKGROUND: The treatment of MOH is challenging, especially when withdrawal headache manifests during the cessation of overused medication. Although systemic corticosteroids have been empirically used to reduce withdrawal headaches, their efficacy on the long-term outcomes of MOH has not been documented. METHODS: This was a post hoc analysis of the RELEASE study. The RELEASE is an ongoing multicenter observational cohort study in which patients with MOH have been recruited from seven hospitals in Korea since April 2020. Clinical characteristics, disease profiles, treatments, and outcomes were assessed at baseline and specific time points. We analyzed the effect of prednisolone on MOH reversal at 3 months. RESULTS: Among the 309 patients enrolled during the study period, prednisolone was prescribed to 59/309 (19.1%) patients at a dose ranging from 10 to 40 mg/day for 5-14 days; 228/309 patients (73.8%) completed the 3-month follow-up period. The MOH reversal rates at 3 months after baseline were 76% (31/41) in the prednisolone group and 57.8% (108/187) in the non-prednisolone group (p = 0.034). The effect of steroids remained significant (adjusted odds ratio 2.78, 95% confidence interval 1.27-6.1, p = 0.010) after adjusting for the number of monthly headache days at baseline, mode of discontinuation of overused medication, use of early preventive medications, and the number of preventive medications combined. CONCLUSIONS: Although our observational study could not draw a definitive conclusion, prednisolone may be effective in the treatment of MOH.


Assuntos
Transtornos da Cefaleia Secundários , Prednisolona , Humanos , Prednisolona/efeitos adversos , Transtornos da Cefaleia Secundários/terapia , Sistema de Registros , Cefaleia/induzido quimicamente , Analgésicos/uso terapêutico
17.
Acta Pharmacol Sin ; 45(2): 327-338, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-37845344

RESUMO

Tricyclic antidepressants (TCAs) are widely used to treat depression and anxiety-related mood disorders. But evidence shows that TCAs elevate blood glucose levels and inhibit insulin secretion, suggesting that TCAs are a risk factor, particularly for individuals with diabetes. Curcumin is a bioactive molecule from the rhizome of the Curcuma longa plant, which has shown both antidepressant and anti-diabetic activities. In the present study, we investigated the protective effect of curcumin against desipramine-induced apoptosis in ß cells and the underlying molecular mechanisms. In the mouse forced swimming test (FST), we found that lower doses of desipramine (5 and 10 mg/kg) or curcumin (2.5 mg/kg) alone did not affect the immobility time, whereas combined treatment with curcumin (2.5 mg/kg) and desipramine (5, 10 mg/kg) significantly decreased the immobility time. Furthermore, desipramine dose-dependently inhibited insulin secretion and elevated blood glucose levels, whereas the combined treatment normalized insulin secretion and blood glucose levels. In RIN-m5F pancreatic ß-cells, desipramine (10 µM) significantly reduced the cell viability, whereas desipramine combined with curcumin dose-dependently prevented the desipramine-induced impairment in glucose-induced insulin release, most effectively with curcumin (1 and 10 µM). We demonstrated that desipramine treatment promoted the cleavage and activation of Caspase 3 in RIN-m5F cells. Curcumin treatment inhibited desipramine-induced apoptosis, increased mitochondrial membrane potential and Bcl-2/Bax ratio. Desipramine increased the generation of reactive oxygen species, which was reversed by curcumin treatment. Curcumin also inhibited the translocation of forkhead box protein O1 (FOXO1) from the cytoplasm to the nucleus and suppressed the binding of A-kinase anchor protein 150 (AKAP150) to protein phosphatase 2B (PP2B, known as calcineurin) that was induced by desipramine. These results suggest that curcumin protects RIN-m5F pancreatic ß-cells against desipramine-induced apoptosis by inhibiting the phosphoinositide 3-kinase/AKT/FOXO1 pathway and the AKAP150/PKA/PP2B interaction. This study suggests that curcumin may have therapeutic potential as an adjunct to antidepressant treatment.


Assuntos
Curcumina , Camundongos , Animais , Curcumina/farmacologia , Desipramina/farmacologia , Glicemia , Fosfatidilinositol 3-Quinases/metabolismo , Apoptose , Antidepressivos/farmacologia
18.
Ann Vasc Surg ; 2024 Jul 13.
Artigo em Inglês | MEDLINE | ID: mdl-39009117

RESUMO

BACKGROUND: Venoactive drugs (VADs) based on Vitis vinifera extract are widely used in Korea. However, studies on the clinical effects and head-to-head comparisons with other groups of VADs are limited. This trial aimed to evaluate whether Vitis vinifera seed extract was non-inferior to the micronized purified flavonoid fraction (MPFF) in relieving venous symptoms and improving quality of life in patients with chronic venous disease (CVD). METHODS: In this double-blind prospective randomized trial, patients from 13 hospitals, who were diagnosed with venous incompetence by duplex ultrasound and classified as clinical class 1, 2, or 3 in the Clinical, Etiological, Anatomical, and Pathophysiological classifications were enrolled. The primary outcome was the change in the Chronic Venous Disease Quality of Life Questionnaire (CIVIQ-20) score at 8 weeks from baseline. Secondary outcomes included changes in the Aberdeen Varicose Vein Questionnaire (AVVQ), visual analog scale (VAS), and Venous Clinical Severity Score (VCSS) at 4- and 8 weeks from baseline. Moreover, the change in leg circumferences was measured at 8 weeks and compared to baseline. RESULTS: In total, 303 patients were enrolled and randomly assigned to receive either Vitis vinifera seed extract (n = 154) or MPFF (n = 149). The CIVIQ-20 scores at 8 weeks were significantly reduced compared to those at baseline in both groups. No significant inter-group difference in the change of CIVIQ-20 at 8 weeks from baseline was observed (-8.31 ± 14.63 vs. -10.35 ± 14.38, P = 0.29, 95% confidence interval [CI] -1.65 to 5.72). The lower limit of the 95% CI was within the predefined noninferiority margin of 6.9. Furthermore, the AVVQ, VAS, and VCSS scores significantly decreased at 4- and 8 weeks after randomization compared with baseline in both groups. No significant differences were observed in the reduction of each score between groups. The calf circumference measured at 8 weeks was significantly reduced compared to that at baseline in patients receiving Vitis vinifera seed extract. CONCLUSIONS: Vitis vinifera seed extract was non-inferior to MPFF in relieving venous symptoms and improving the quality of life in patients with CVD.

19.
Skeletal Radiol ; 53(8): 1465-1471, 2024 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-38443696

RESUMO

PURPOSE: We identified limb misalignment by applying personalized axial force while the limb was in a supine position to mimic a standing posture. This study aimed to confirm the accuracy of evaluating lower limb alignment using supine weight-bearing CT scanograms. METHODS: We prospectively compared measurements of the weight-bearing line ratio (WBL), hip-knee-ankle (HKA) angle, and joint convergence angle (JLCA) in 46 sets of supine weight-bearing CT scanograms with those obtained from full-length standing anteroposterior lower extremity radiographs. We achieved the weight-bearing CT scanograms by applying six different levels of axial force: zero, 1/5 of body weight, 2/5 of body weight, 3/5 of body weight, 4/5 of body weight, and full body weight. We assessed the impact of age, body mass index, HKA, and JLCA on the observed mechanical axis deviation differences between the two methods. RESULT: The average absolute difference between standing radiographs and supine CT scanograms was 4.32% for the WBL ratio (p < 0.05), 1.25° for HKA (p < 0.05), and 0.46 for JLCA (p < 0.05). The mean absolute difference was minimal when applying full body weight axial pressure during CT scanograms (p > 0.05). Age, body mass index, HKA, and JLCA had no effect on the deviation in the mechanical axis measurements obtained through supine weight-bearing CT scanograms with full body weight. CONCLUSION: No significant differences were found in assessing lower limb alignment between standing radiographs and supine weight-bearing CT scanograms with full body weight. Weight-bearing CT scanograms prove to be a valuable method for assessing lower limb alignment while in a supine position.


Assuntos
Extremidade Inferior , Tomografia Computadorizada por Raios X , Adulto , Idoso , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Extremidade Inferior/diagnóstico por imagem , Estudos Prospectivos , Reprodutibilidade dos Testes , Posição Ortostática , Decúbito Dorsal , Tomografia Computadorizada por Raios X/métodos , Suporte de Carga
20.
Molecules ; 29(7)2024 Mar 28.
Artigo em Inglês | MEDLINE | ID: mdl-38611784

RESUMO

A new structurally simple fluorescent CP probe based on chromone was designed and synthesized, and its structure was fully characterized using various analytical techniques. The CP probe displays a high selectivity and sensitivity for sensing Fe3+ with a "turn-off" fluorescence response over other metal ions in a DMSO/H2O (4:1, v/v) solution. The experiment results show that the CP probe is stable over a wide pH range of 2.0-12.0. The detection limit for Fe3+ was calculated to be 0.044 µmol•L-1. The molar ratio method indicated that the binding mode between the CP probe and Fe3+ is a 1:1 complex formation. HR-MS and density functional theory (DFT) calculations were also performed to further confirm the recognition mechanism. Both fluorescence imaging experiments and the MTT assay demonstrated that the CP probe was suitable for detecting intracellular Fe3+ and no significant cytotoxicity in living cells.


Assuntos
Cromonas , Imagem Óptica , Corantes Fluorescentes , Reconhecimento Psicológico , Projetos de Pesquisa
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