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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.
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
4.
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
5.
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
6.
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
7.
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
8.
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
9.
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
10.
J Biol Chem ; 288(38): 27607-27618, 2013 Sep 20.
Artigo em Inglês | MEDLINE | ID: mdl-23902794

RESUMO

Gene expression can be regulated through factors that direct RNA polymerase to the correct promoter sequence at the correct time. Bacteriophage T4 controls its development in this way using phage proteins that interact with host RNA polymerase. Using a process called σ appropriation, the T4 co-activator AsiA structurally remodels the σ(70) subunit of host RNA polymerase, while a T4 activator, MotA, engages the C terminus of σ(70) and binds to a DNA promoter element, the MotA box. Structures for the N-terminal (NTD) and C-terminal (CTD) domains of MotA are available, but no structure exists for MotA with or without DNA. We report the first molecular map of the MotA/DNA interaction within the σ-appropriated complex, which we obtained by using the cleaving reagent, iron bromoacetamidobenzyl-EDTA (FeBABE). We conjugated surface-exposed, single cysteines in MotA with FeBABE and performed cleavage reactions in the context of stable transcription complexes. The DNA cleavage sites were analyzed using ICM Molsoft software and three-dimensional physical models of MotA(NTD), MotA(CTD), and the DNA to investigate shape complementarity between the protein and the DNA and to position MotA on the DNA. We found that the unusual "double wing" motif present within MotA(CTD) resides in the major groove of the MotA box. In addition, we have used surface plasmon resonance to show that MotA alone is in a very dynamic equilibrium with the MotA element. Our results demonstrate the utility of fine resolution FeBABE mapping to determine the architecture of protein-DNA complexes that have been recalcitrant to traditional structure analyses.


Assuntos
Bacteriófago T4/química , DNA Viral/química , Proteínas de Ligação a DNA/química , RNA Polimerases Dirigidas por DNA/química , Proteínas de Escherichia coli/química , Modelos Moleculares , Regiões Promotoras Genéticas , Fator sigma/química , Fatores de Transcrição/química , Proteínas Virais/química , Motivos de Aminoácidos , Bacteriófago T4/genética , Bacteriófago T4/metabolismo , DNA Viral/genética , DNA Viral/metabolismo , Proteínas de Ligação a DNA/genética , Proteínas de Ligação a DNA/metabolismo , RNA Polimerases Dirigidas por DNA/genética , RNA Polimerases Dirigidas por DNA/metabolismo , Escherichia coli/química , Escherichia coli/genética , Escherichia coli/metabolismo , Escherichia coli/virologia , Proteínas de Escherichia coli/genética , Proteínas de Escherichia coli/metabolismo , Estrutura Terciária de Proteína , Fator sigma/genética , Fator sigma/metabolismo , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo , Proteínas Virais/genética , Proteínas Virais/metabolismo
11.
Mol Microbiol ; 90(6): 1262-76, 2013 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-24134710

RESUMO

Cyclic di-GMP (c-di-GMP) controls the transition between sessility and motility in many bacterial species. This regulation is achieved by a variety of mechanisms including alteration of transcription initiation and inhibition of flagellar function. How c-di-GMP inhibits the motility of Vibrio cholerae has not been determined. FlrA, a homologue of the c-di-GMP binding Pseudomonas aeruginosa motility regulator FleQ, is the master regulator of the V. cholerae flagellar biosynthesis regulon. Here we show that binding of c-di-GMP to FlrA abrogates binding of FlrA to the promoter of the flrBC operon, deactivating expression of the flagellar biosynthesis regulon. FlrA does not regulate expression of extracellular Vibrio polysaccharide (VPS) synthesis genes. Mutation of the FlrA amino acids R135 and R176 to histidine abrogates binding of c-di-GMP to FlrA, rendering FlrA active in the presence of high levels of c-di-GMP. Surprisingly, c-di-GMP still inhibited the motility of V. cholerae only expressing the c-di-GMP blind FlrA(R176H) mutant. We determined that this flagellar transcription-independent inhibition is due to activation of VPS production by c-di-GMP. Therefore, c-di-GMP prevents motility of V. cholerae by two distinct but functionally redundant mechanisms.


Assuntos
Proteínas de Bactérias/metabolismo , GMP Cíclico/análogos & derivados , Regulação Bacteriana da Expressão Gênica , Polissacarídeos Bacterianos/metabolismo , Transcrição Gênica , Vibrio cholerae/fisiologia , Arginina/metabolismo , Proteínas de Bactérias/química , Proteínas de Bactérias/genética , Sítios de Ligação , GMP Cíclico/fisiologia , Flagelos/metabolismo , Histidina/metabolismo , Modelos Moleculares , Movimento , Mutação , Óperon , Conformação Proteica , Estrutura Terciária de Proteína , Vibrio cholerae/genética , Vibrio cholerae/metabolismo
12.
Retrovirology ; 11: 86, 2014 Oct 02.
Artigo em Inglês | MEDLINE | ID: mdl-25274545

RESUMO

BACKGROUND: The HIV-1 envelope glycoprotein (Env) undergoes conformational changes that mediate fusion between virus and host cell membranes. These changes involve transient exposure of two heptad-repeat domains (HR1 and HR2) in the gp41 subunit and their subsequent self-assembly into a six-helix bundle (6HB) that drives fusion. Env residues and features that influence conformational changes and the rate of virus entry, however, are poorly understood. Peptides corresponding to HR1 and HR2 (N and C peptides, respectively) interrupt formation of the 6HB by binding to the heptad repeats of a fusion-intermediate conformation of Env, making the peptides valuable probes for studying Env conformational changes. RESULTS: Using a panel of Envs that are resistant to N-peptide fusion inhibitors, we investigated relationships between virus entry kinetics, 6HB stability, and resistance to peptide fusion inhibitors to elucidate how HR1 and HR2 mutations affect Env conformational changes and virus entry. We found that gp41 resistance mutations increased 6HB stability without increasing entry kinetics. Similarly, we show that increased 6HB thermodynamic stability does not correlate with increased entry kinetics. Thus, N-peptide fusion inhibitors do not necessarily select for Envs with faster entry kinetics, nor does faster entry kinetics predict decreased potency of peptide fusion inhibitors. CONCLUSIONS: These findings provide new insights into the relationship between 6HB stability and viral entry kinetics and mechanisms of resistance to inhibitors targeting fusion-intermediate conformations of Env. These studies further highlight how residues in HR1 and HR2 can influence virus entry by altering stability of the 6HB and possibly other conformations of Env that affect rate-limiting steps in HIV entry.


Assuntos
Farmacorresistência Viral , Proteína gp41 do Envelope de HIV/química , Inibidores da Fusão de HIV/metabolismo , HIV-1/efeitos dos fármacos , Complexos Multiproteicos/química , Multimerização Proteica , Internalização do Vírus/efeitos dos fármacos , Linhagem Celular , Proteína gp41 do Envelope de HIV/genética , Proteína gp41 do Envelope de HIV/metabolismo , HIV-1/genética , HIV-1/fisiologia , Humanos , Cinética , Proteínas Mutantes/química , Proteínas Mutantes/genética , Proteínas Mutantes/metabolismo , Conformação Proteica , Estabilidade Proteica , Termodinâmica
13.
iScience ; 26(10): 107997, 2023 Oct 20.
Artigo em Inglês | MEDLINE | ID: mdl-37810249

RESUMO

15-keto-PGE2 is one of the eicosanoids with anti-inflammatory properties. In this study, we demonstrated that 15-keto-PGE2 post-translationally modified the nuclear factor κ-light-chain-enhancer of activated B cells (NF-κB) subunits p105/p50 and p65 at Cys59 and Cys120 sites, respectively, hence inhibiting the activation of NF-κB signaling in macrophages. In mice fed a high-fat and high-sucrose diet (HFHSD), 15-keto-PGE2 treatment reduced pro-inflammatory cytokines and fasting glucose levels. In mice with non-alcoholic steatohepatitis (NASH) induced by a prolonged HFHSD, 15-keto-PGE2 treatment significantly decreased liver inflammation, lowered serum levels of alanine transaminase (ALT) and aspartate transferase (AST), and inhibited macrophage infiltration. It also reduced lipid droplet size and downregulated key regulators of lipogenesis. These findings highlight the potential of 15-keto-PGE2, through NF-κB modification, in preventing the development and progression of steatohepatitis, emphasizing the significance of endogenous lipid mediators in the inflammatory response.

14.
Sci Rep ; 13(1): 2662, 2023 02 15.
Artigo em Inglês | MEDLINE | ID: mdl-36792682

RESUMO

Transcutaneous electrical nerve stimulator (TENS) has been demonstrated to be beneficial in glycemic control in animal models, but its application in humans has not been well studied. We randomly assigned 160 patients with type 2 diabetes on oral antidiabetic drugs 1:1 to the TENS study device (n = 81) and placebo (n = 79). 147 (92%) randomized participants (mean [SD] age 59 [10] years, 92 men [58%], mean [SD] baseline HbA1c level 8.1% [0.6%]) completed the trial. At week 20, HbA1c decreased from 8.1% to 7.9% in the TENS group (- 0.2% [95% CI - 0.4% to - 0.1%]) and from 8.1% to 7.8% in the placebo group (- 0.3% [95% CI - 0.5% to - 0.2%]) (P = 0.821). Glycemic variability, measured as mean amplitude of glycemic excursion (MAGE) at week 20 were significantly different in the TENS group vs. the placebo group (66 mg/dL [95% CI 58, 73] vs. 79 mg/dL [95% CI 72, 87]) (P = 0.009). Our study provides the clinical evidence for the first time in humans that TENS does not demonstrate a statistically significant HbA1c reduction. However, it is a safe complementary therapy to improve MAGE in patients with type 2 diabetes.


Assuntos
Diabetes Mellitus Tipo 2 , Estimulação Elétrica Nervosa Transcutânea , Masculino , Humanos , Pessoa de Meia-Idade , Diabetes Mellitus Tipo 2/tratamento farmacológico , Controle Glicêmico , Hipoglicemiantes/uso terapêutico
15.
Obes Surg ; 33(10): 3035-3050, 2023 10.
Artigo em Inglês | MEDLINE | ID: mdl-37612578

RESUMO

BACKGROUND: The superior effects of gastric bypass surgery in preventing cardiovascular diseases compared with sleeve gastrectomy are well-established. However, whether these effects are independent of weight loss is not known. METHODS: In this retrospective cohort study, we compared the change in cardiometabolic risks of 1073 diabetic patients undergoing Roux-en-Y gastric bypass (RYGB) (n = 265), one-anastomosis gastric bypass (OAGB) (n = 619), and sleeve gastrectomy (SG) (n = 189) with equivalent weight loss from the Min-Shen General Hospital. Propensity score-weighting, multivariate regression, and matching were performed to adjust for baseline differences. RESULTS: After 12 months, OAGB and, to a lesser extent, RYGB exhibited superior effects on glycemic control compared with SG in patients with equivalent weight loss. The effect was significant in patients with mild-to-modest BMI reduction but diminished in patients with severe BMI reduction. RYGB and OAGB had significantly greater effects in lowering total and low-density lipoprotein cholesterol than SG, regardless of weight loss. The results of matching patients with equivalent weight loss yielded similar results. The longer length of bypassed biliopancreatic (BP) limbs was correlated with a greater decrease in glycemic levels, insulin resistance index, lipids, C-reactive protein (CRP) levels, and creatinine levels in patients receiving RYBG. It was correlated with greater decreases in BMI, fasting insulin, insulin resistance index, and C-reactive protein levels in patients receiving OAGB. CONCLUSION: Diabetic patients receiving OAGB and RYGB had lower glucose and cholesterol levels compared with SG independent of weight loss. Our results suggest diabetic patients with cardiovascular risk factors such as hypercholesterolemia to receive bypass surgery.


Assuntos
Diabetes Mellitus , Derivação Gástrica , Resistência à Insulina , Obesidade Mórbida , Humanos , Proteína C-Reativa , Pontuação de Propensão , Estudos Retrospectivos , Obesidade Mórbida/cirurgia , Insulina , Redução de Peso , LDL-Colesterol , Gastrectomia , Glucose
16.
Nat Commun ; 14(1): 5971, 2023 09 25.
Artigo em Inglês | MEDLINE | ID: mdl-37749090

RESUMO

Obesity and type 2 diabetes have reached pandemic proportion. ALDH2 (acetaldehyde dehydrogenase 2, mitochondrial) is the key metabolizing enzyme of acetaldehyde and other toxic aldehydes, such as 4-hydroxynonenal. A missense Glu504Lys mutation of the ALDH2 gene is prevalent in 560 million East Asians, resulting in reduced ALDH2 enzymatic activity. We find that male Aldh2 knock-in mice mimicking human Glu504Lys mutation were prone to develop diet-induced obesity, glucose intolerance, insulin resistance, and fatty liver due to reduced adaptive thermogenesis and energy expenditure. We find reduced activity of ALDH2 of the brown adipose tissue from the male Aldh2 homozygous knock-in mice. Proteomic analyses of the brown adipose tissue from the male Aldh2 knock-in mice identifies increased 4-hydroxynonenal-adducted proteins involved in mitochondrial fatty acid oxidation and electron transport chain, leading to markedly decreased fatty acid oxidation rate and mitochondrial respiration of brown adipose tissue, which is essential for adaptive thermogenesis and energy expenditure. AD-9308 is a water-soluble, potent, and highly selective ALDH2 activator. AD-9308 treatment ameliorates diet-induced obesity and fatty liver, and improves glucose homeostasis in both male Aldh2 wild-type and knock-in mice. Our data highlight the therapeutic potential of reducing toxic aldehyde levels by activating ALDH2 for metabolic diseases.


Assuntos
Diabetes Mellitus Tipo 2 , Fígado Gorduroso , Humanos , Masculino , Camundongos , Animais , Diabetes Mellitus Tipo 2/genética , Proteômica , Aldeído-Desidrogenase Mitocondrial/genética , Aldeído-Desidrogenase Mitocondrial/metabolismo , Mutação , Obesidade/genética , Ácidos Graxos , Aldeído Desidrogenase/genética , Aldeído Desidrogenase/metabolismo
17.
Oral Oncol ; 133: 106029, 2022 10.
Artigo em Inglês | MEDLINE | ID: mdl-35870330

RESUMO

OBJECTIVES: The mainstay of oral cavity cancer treatment is surgery, often with adjuvant therapies. However, patients often present with locally advanced disease and downstaging would render surgery more feasible. We evaluated hypofractionated radiation therapy (QUAD Shot) prior to definitive surgery for head and neck cancers, with a goal of downstaging. MATERIALS AND METHODS: Eighteen patients with primary head and neck malignancy, predominantly locally advanced oral cavity cancers, received QUAD Shot radiation therapy from June 2016 to July 2021. External beam radiation therapy was delivered to the primary lesion in four fractions over two days, two fractions/day at least six hours apart with total dose ranging from 1400 cGy to 1500 cGy. Twelve patients proceeded to definitive surgery. RESULTS: Of the twelve patients receiving surgery, one had complete response to radiation therapy with no pathological disease seen at surgery. Four patients had a partial response, defined as downstaging on final pathology. Five patients showed no response, and two had progressive disease defined as upstaging on final pathology. Seven patients had radiographic primary tumor shrinkage ≥ 0.5 cm following Quad Shot. The Quad Shot was tolerated well with no reported adverse effects. CONCLUSION: Discrepancies between clinical- and pathological-staging are common and expected. However, ∼40 % of our patients experienced downstaging following QUAD Shot. Thus, neoadjuvant radiation therapy may be viable for temporizing tumor growth while awaiting surgery, or for downstaging and thus facilitating more technically feasible and less morbid surgery for locally advanced head and neck cancers.


Assuntos
Neoplasias de Cabeça e Pescoço , Neoplasias Bucais , Humanos , Neoplasias Bucais/radioterapia , Neoplasias Bucais/cirurgia , Terapia Neoadjuvante , Estadiamento de Neoplasias
18.
BMJ Open ; 12(6): e059856, 2022 06 13.
Artigo em Inglês | MEDLINE | ID: mdl-35697446

RESUMO

OBJECTIVE: To evaluate medication adherence among patients with hepatitis B-related cirrhosis who developed decompensation and mortality, and to examine the association between medication adherence and patients' disease outcomes. DESIGN: In this retrospective case-control study, patients aged over 20 years old and diagnosed with both chronic hepatitis B and cirrhosis from 2007 to 2016 are identified using a population-based medical claims database. Two prognosis endpoints (decompensation and mortality) are used, respectively, to classify subjects into two different case-control sets. Study groups are propensity-score matched. Medication possession ratio (MPR) is used as a measure of treatment adherence for oral antiviral drugs, and conditional logistic regression models are used to estimate the odds of decompensation and mortality after accounting for MPR and other covariates. RESULTS: Between decompensated and compensated patients, longer term treatment adherence is seen higher in the compensated group versus the decompensated group: 1-year MPR (0.65±0.43 vs 0.57±0.53) and 6-month MPR (0.79±0.52 vs 0.76±0.79). On the contrary, 3-month adherence is higher in the decompensated group (1.00±1.15 vs 0.96±0.79). For patients with and without mortality, drug adherence is ubiquitously higher in the alive group regardless of follow-up length: 1-year MPR (0.62±0.44 vs 0.50±0.51), 6-month MPR (0.78±0.62 vs 0.69±0.72) and 3-month MPR (0.97±0.91 vs 0.96±1.12). After accounting for confounding variables, we find that the likelihood of complicated cirrhosis is significantly lower in more adherent patients and the benefit increases with more persistent adherence (log 1-year MPR OR: 0.75, 95% CI: 0.73 to 0.77). Similar results are observed for the adjusted likelihood of mortality (log 1-year MPR OR: 0.70, 95% CI: 0.68 to 0.72). CONCLUSIONS: Long-term patient adherence to oral antiviral therapy remains inadequate in patients with hepatitis B virus-related cirrhosis. Their adherence to oral antiviral therapy appears to be inversely associated with decompensation and mortality.


Assuntos
Hepatite B , Adesão à Medicação , Adulto , Idoso , Antivirais/uso terapêutico , Estudos de Casos e Controles , Humanos , Cirrose Hepática/tratamento farmacológico , Estudos Retrospectivos , Adulto Jovem
19.
J Med Case Rep ; 16(1): 364, 2022 Oct 05.
Artigo em Inglês | MEDLINE | ID: mdl-36195921

RESUMO

BACKGROUND: Primary squamous cell carcinoma of the thyroid is a very rare malignancy with aggressive growth and poor prognosis. There is currently no consensus for treatment modality, however, most patients with primary squamous cell carcinoma of the thyroid are treated with surgery and adjuvant chemoradiation. CASE PRESENTATION: We report a rare case of primary squamous cell carcinoma of the thyroid in a 68-year-old White male who underwent chemoradiation and palliative immunotherapy after declining surgery. He was treated with intensity-modulated radiation therapy to 70 Gy in 35 fractions, with concurrent carboplatin-paclitaxel and palliative pembrolizumab. Local thyroid disease recurrence occurred at 6 months post-chemoradiation, and the patient died at 16 months post-chemoradiation. CONCLUSIONS: This is the first case report demonstrating the use of pembrolizumab as palliative therapy for primary squamous cell carcinoma of the thyroid. Our study also highlights the importance of chemoradiation in decreasing primary mass size and immunotherapy in preventing metastatic disease progression.


Assuntos
Carcinoma de Células Escamosas , Cuidados Paliativos , Idoso , Carboplatina/uso terapêutico , Carcinoma de Células Escamosas/patologia , Quimiorradioterapia Adjuvante , Humanos , Imunoterapia , Masculino , Recidiva Local de Neoplasia/terapia , Paclitaxel , Glândula Tireoide/patologia
20.
Sci Rep ; 12(1): 8025, 2022 05 16.
Artigo em Inglês | MEDLINE | ID: mdl-35577822

RESUMO

Melatonin exerts a wide range of effects among various tissues and organs. However, there is currently no study to investigate the genetic determinants of melatonin secretion. Here, we conducted a genome-wide association study (GWAS) for melatonin secretion using morning urine 6-hydroxymelatonin sulfate-to-creatinine ratio (UMCR). We initially enrolled 5000 participants from Taiwan Biobank in this study. After excluding individuals that did not have their urine collected in the morning, those who had history of neurological or psychiatric disorder, and those who failed to pass quality control, association of single nucleotide polymorphisms with log-transformed UMCR adjusted for age, sex and principal components of ancestry were analyzed. A second model additionally adjusted for estimated glomerular filtration rate (eGFR). A total of 2373 participants underwent the genome-wide analysis. Five candidate loci associated with log UMCR (P value ranging from 6.83 × 10-7 to 3.44 × 10-6) encompassing ZFHX3, GALNT15, GALNT13, LDLRAD3 and intergenic between SEPP1 and FLJ32255 were identified. Similar results were yielded with further adjustment for eGFR. Interestingly, the identified genes are associated with circadian behavior, neuronal differentiation, motor disorders, anxiety, and neurodegenerative diseases. We conducted the first GWAS for melatonin secretion and identified five candidate genetic loci associated with melatonin level. Replication and functional studies are needed in the future.


Assuntos
Estudo de Associação Genômica Ampla , Melatonina , Ritmo Circadiano , Loci Gênicos , Humanos , Melatonina/genética , Melatonina/metabolismo , Polimorfismo de Nucleotídeo Único
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