Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 44
Filtrar
1.
bioRxiv ; 2024 May 18.
Artigo em Inglês | MEDLINE | ID: mdl-38798583

RESUMO

The rapid and sustained proliferation in cancer cells requires accelerated protein synthesis. Accelerated protein synthesis and disordered cell metabolism in cancer cells greatly increase the risk of translation errors. ribosome-associated quality control (RQC) is a recently discovered mechanism for resolving ribosome collisions caused by frequent translation stalls. The role of the RQC pathway in cancer initiation and progression remains controversial and confusing. In this study, we investigated the pathogenic role of mitochondrial stress-induced protein carboxyl-terminal terminal alanine and threonine tailing (msiCAT-tailing) in glioblastoma (GBM), which is a specific RQC response to translational arrest on the outer mitochondrial membrane. We found that msiCAT-tailed mitochondrial proteins frequently exist in glioblastoma stem cells (GSCs). Ectopically expressed msiCAT-tailed mitochondrial ATP synthase F1 subunit alpha (ATP5α) protein increases the mitochondrial membrane potential and blocks mitochondrial permeability transition pore (MPTP) formation/opening. These changes in mitochondrial properties confer resistance to staurosporine (STS)-induced apoptosis in GBM cells. Therefore, msiCAT-tailing can promote cell survival and migration, while genetic and pharmacological inhibition of msiCAT-tailing can prevent the overgrowth of GBM cells. Highlights: The RQC pathway is disturbed in glioblastoma (GBM) cellsmsiCAT-tailing on ATP5α elevates mitochondrial membrane potential and inhibits MPTP openingmsiCAT-tailing on ATP5α inhibits drug-induced apoptosis in GBM cellsInhibition of msiCAT-tailing impedes overall growth of GBM cells.

2.
J Immunol ; 212(9): 1442-1449, 2024 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-38436421

RESUMO

Protein arginine methyltransferases (PRMTs) modify diverse protein targets and regulate numerous cellular processes; yet, their contributions to individual effector T cell responses during infections are incompletely understood. In this study, we identify PRMT5 as a critical regulator of CD4+ T follicular helper cell (Tfh) responses during influenza virus infection in mice. Conditional PRMT5 deletion in murine T cells results in an almost complete ablation of both Tfh and T follicular regulatory populations and, consequently, reduced B cell activation and influenza-specific Ab production. Supporting a potential mechanism, we observe elevated surface expression of IL-2Rα on non-T regulatory effector PRMT5-deficient T cells. Notably, IL-2 signaling is known to negatively impact Tfh differentiation. Collectively, our findings identify PRMT5 as a prominent regulator of Tfh programming, with potential causal links to IL-2 signaling.


Assuntos
Influenza Humana , Infecções por Orthomyxoviridae , Orthomyxoviridae , Animais , Humanos , Camundongos , Diferenciação Celular , Centro Germinativo , Interleucina-2/metabolismo , Infecções por Orthomyxoviridae/metabolismo , Células T Auxiliares Foliculares
3.
Child Dev ; 2024 Feb 14.
Artigo em Inglês | MEDLINE | ID: mdl-38353466

RESUMO

Improved survival of preterm low birthweight (LBW) infants due to advances in neonatal care has brought issues such as postnatal development trajectories to the foreground. This study pools evidence from three cluster-randomized experiments evaluating community-based psychosocial stimulation programs conducted from 2014 to 2017 that included 3571 rural Chinese children aged 6-24 months (51.1% male, 96.2% Han Chinese). The risk of severe cognitive delay was found to be 26.5 percentage points higher for preterm LBW children than for their peers at age 2.5, with a prevalence rate of 48.3%. Results show that psychosocial stimulation interventions can improve child cognitive development at scale, with beneficial impacts on child cognition disproportionately larger for preterm LBW children, helping them to catch up developmentally.

4.
ACS Appl Bio Mater ; 7(1): 406-415, 2024 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-38148527

RESUMO

The purpose of tissue engineering is to reconstruct parts of injured tissues and to resolve the shortage of organ donations. However, the main concern is the limited size of engineered tissue due to insufficient oxygen and nutrition distribution in large three-dimensional (3D) tissue constructs. To provide better support for cells inside the scaffolds, the vascularization of blood vessels within the scaffold could be a solution. This study compared the effects of different culturing systems using human adipose tissue-derived stem/stromal cells (ASCs), human umbilical vein endothelial cells (HUVECs), and coculture of ASCs and HUVECs in 3D-bioprinted gelatin methacrylate (GelMA) hydrogel constructs. The in vitro results showed that the number of live cells was highest in the coculture of ASCs and HUVECs in the GelMA hydrogel after culturing for 21 days. Additionally, the tubular structure was the most abundant in the GelMA hydrogel, containing both ASCs and HUVECs. In the in vivo test, blood vessels were present in both the HUVECs and the coculture of ASCs and HUVECs hydrogels implanted in mice. However, the blood vessel density was the highest in the HUVEC and ASC coculture groups. These findings indicate that the 3D-bioprinted GelMA hydrogel coculture system could be a promising biomaterial for large tissue engineering applications.


Assuntos
Gelatina , Metacrilatos , Humanos , Animais , Camundongos , Células Endoteliais da Veia Umbilical Humana , Gelatina/farmacologia , Gelatina/química , Tecido Adiposo , Hidrogéis/química
5.
Physiol Rep ; 11(10): e15696, 2023 05.
Artigo em Inglês | MEDLINE | ID: mdl-37226398

RESUMO

The voltage-gated Nav 1.5 channels mediate the fast Na+ current (INa ) in cardiomyocytes initiating action potentials and cardiac contraction. Downregulation of INa , as occurs in Brugada syndrome (BrS), causes ventricular arrhythmias. The present study investigated whether the Wnt/ß-catenin signaling regulates Nav 1.5 in human-induced pluripotent stem cell-derived cardiomyocytes (iPSC-CMs). In healthy male and female iPSC-CMs, activation of Wnt/ß-catenin signaling by CHIR-99021 reduced (p < 0.01) both Nav 1.5 protein and SCN5A mRNA. In iPSC-CMs from a BrS patient, both Nav 1.5 protein and peak INa were reduced compared to those in healthy iPSC-CMs. Treatment of BrS iPSC-CMs with Wnt-C59, a small-molecule Wnt inhibitor, led to a 2.1-fold increase in Nav 1.5 protein (p = 0.0005) but surprisingly did not affect SCN5A mRNA (p = 0.146). Similarly, inhibition of Wnt signaling using shRNA-mediated ß-catenin knockdown in BrS iPSC-CMs led to a 4.0-fold increase in Nav 1.5, which was associated with a 4.9-fold increase in peak INa but only a 2.1-fold increase in SCN5A mRNA. The upregulation of Nav 1.5 by ß-catenin knockdown was verified in iPSC-CMs from a second BrS patient. This study demonstrated that Wnt/ß-catenin signaling inhibits Nav 1.5 expression in both male and female human iPSC-CMs, and inhibition of Wnt/ß-catenin signaling upregulates Nav 1.5 in BrS iPSC-CMs through both transcriptional and posttranscriptional mechanisms.


Assuntos
Síndrome de Brugada , Células-Tronco Pluripotentes Induzidas , Canal de Sódio Disparado por Voltagem NAV1.5 , Via de Sinalização Wnt , Feminino , Humanos , Masculino , beta Catenina , Miócitos Cardíacos , Canal de Sódio Disparado por Voltagem NAV1.5/genética
6.
Front Med (Lausanne) ; 10: 1138690, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36936232

RESUMO

Background: Ovary is a common organ site involved by endometriosis. We previously found that fallopian tube may contribute to the histogenesis of ovarian endometriosis. The finding was novel and requires further studies. We addressed this issue by examining a differentially expressed gene folate receptor alpha (FOLR1) and its protein (FRA) in this study. Results: A total of 144 tissue samples were studied. These included 32-paired tubal-endometrial-ovarian endometriosis samples (n = 96), 18 samples of ovarian endometriosis without corresponding fallopian tube or endometrium, and 30 ovarian tissue samples with ovarian surface epithelia but without endometriosis. Multiple comparisons among groups of ovarian endometriosis, normal fallopian tube and benign endometrium were performed. FOLR1 was highly expressed in the epithelia of fallopian tube and ovarian endometriosis, with paired endometrial samples showing a significantly lower level of expression. Similar differential studies for FRA protein were performed through Western blot and immunohistochemistry (IHC). The expression of folate receptor alpha at both mRNA and protein levels in the tissues (fallopian tube or ovarian endometriosis vs. the endometrium) were significantly different (p < 0.001). All ovarian surface mesothelial epithelia showed negative expression of FRA by IHC. Conclusion: The results further support that the fallopian tube may contribute to the development of ovarian endometriosis. Understanding the tubal contribution to ovarian endometriosis should ultimately contribute to ongoing investigative efforts aimed at identifying alternative ways to prevent and treat endometriosis. High level of FRA expression in the fallopian tube and endometriosis might be considered as potential tissue sites for targeted therapy.

7.
J Nucl Cardiol ; 30(4): 1642-1652, 2023 08.
Artigo em Inglês | MEDLINE | ID: mdl-36754934

RESUMO

AIM: The aim of the study was to evaluate the changes in central vascular inflammation measured by FDG PET and myocardial blood flow reserve (MFR) determined by 82Rb PET following therapy with biologic agents for 6 months in patients with psoriatic arthritis (PsA) and/or cutaneous psoriasis (PsO) (group 1) and compare with PsO subjects receiving non-biologic therapy (group 2) and controls (group 3). METHODS AND RESULTS: Target-to-background ratio (TBR) by FDG PET in the most diseased segment of the ascending aorta (TBRmax) was measured to assess vascular inflammation. 82Rb PET studies were used to assess changes in left ventricular MFR. A total of 34 participants were enrolled in the study (11 in group 1, 13 in group 2, and 10 controls). A significant drop in the thoracic aorta uptake was observed in the biologic-treated group (ΔTBRmax: - .46 ± .55) compared to the PsO group treated with non-biologic therapy (ΔTBRmax: .23 ± .67). Those showing response to biologic agents maintained MFR compared to who showed no response. CONCLUSION: In a cohort of psoriasis patients treated with biologics, FDG uptake in the thoracic aorta decreased over the study period. Patients who demonstrated a significant anti-inflammatory response on FDG PET imaging maintained their MFR compared to non-responders.


Assuntos
Artrite Psoriásica , Psoríase , Humanos , Artrite Psoriásica/diagnóstico por imagem , Artrite Psoriásica/tratamento farmacológico , Fluordesoxiglucose F18/uso terapêutico , Estudos Prospectivos , Tomografia por Emissão de Pósitrons , Psoríase/diagnóstico por imagem , Psoríase/tratamento farmacológico , Fatores Biológicos/uso terapêutico , Inflamação/diagnóstico por imagem , Anti-Inflamatórios/uso terapêutico
8.
Commun Biol ; 6(1): 7, 2023 01 04.
Artigo em Inglês | MEDLINE | ID: mdl-36599970

RESUMO

Theca cells serve multiple essential functions during the growth and maturation of ovarian follicles, providing structural, metabolic, and steroidogenic support. While the function of theca during folliculogenesis is well established, their cellular origins and the differentiation hierarchy that generates distinct theca sub-types, remain unknown. Here, we performed single cell multi-omics analysis of primary cell populations purified from human antral stage follicles (1-3 mm) to define the differentiation trajectory of theca/stroma cells. We then corroborated the temporal emergence and growth kinetics of defined theca/stroma subpopulations using human ovarian tissue samples and xenografts of cryopreserved/thawed ovarian cortex, respectively. We identified three lineage specific derivatives termed structural, androgenic, and perifollicular theca cells, as well as their putative lineage-negative progenitor. These findings provide a framework for understanding the differentiation process that occurs in each primordial follicle and identifies specific cellular/molecular phenotypes that may be relevant to either diagnosis or treatment of ovarian pathologies.


Assuntos
Células da Granulosa , Folículo Ovariano , Feminino , Humanos , Células da Granulosa/metabolismo , Folículo Ovariano/metabolismo , Células Tecais/metabolismo , Ovário , Diferenciação Celular
9.
Brief Bioinform ; 25(1)2023 11 22.
Artigo em Inglês | MEDLINE | ID: mdl-38189539

RESUMO

Sequence motif discovery algorithms enhance the identification of novel deoxyribonucleic acid sequences with pivotal biological significance, especially transcription factor (TF)-binding motifs. The advent of assay for transposase-accessible chromatin using sequencing (ATAC-seq) has broadened the toolkit for motif characterization. Nonetheless, prevailing computational approaches have focused on delineating TF-binding footprints, with motif discovery receiving less attention. Herein, we present Cis rEgulatory Motif Influence using de Bruijn Graph (CEMIG), an algorithm leveraging de Bruijn and Hamming distance graph paradigms to predict and map motif sites. Assessment on 129 ATAC-seq datasets from the Cistrome Data Browser demonstrates CEMIG's exceptional performance, surpassing three established methodologies on four evaluative metrics. CEMIG accurately identifies both cell-type-specific and common TF motifs within GM12878 and K562 cell lines, demonstrating its comparative genomic capabilities in the identification of evolutionary conservation and cell-type specificity. In-depth transcriptional and functional genomic studies have validated the functional relevance of CEMIG-identified motifs across various cell types. CEMIG is available at https://github.com/OSU-BMBL/CEMIG, developed in C++ to ensure cross-platform compatibility with Linux, macOS and Windows operating systems.


Assuntos
Algoritmos , Sequenciamento de Cromatina por Imunoprecipitação , Benchmarking , Evolução Biológica , Linhagem Celular
10.
BJR Open ; 4(1): 20210077, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36452057

RESUMO

Diffusion-weighted imaging is increasingly becoming popular in musculoskeletal radiology for its incremental role over conventional MR imaging in the diagnostic strategy and assessment of therapeutic response of bone and soft tissue lesions. This article discusses the technical considerations of diffusion-weighted imaging, how to optimize its performance, and outlines the role of this novel imaging in the identification and characterization of musculoskeletal lesions, such as bone and soft tissue tumors, musculoskeletal infections, arthritis, myopathy, and peripheral neuropathy. The readers can use the newly learned concepts from the presented material containing illustrated case examples to enhance their conventional musculoskeletal imaging and interventional practices and optimize patient management, their prognosis, and outcomes.

11.
Elife ; 112022 09 07.
Artigo em Inglês | MEDLINE | ID: mdl-36069787

RESUMO

Ascorbate (vitamin C) is an essential micronutrient in humans. The severe chronic deficiency of ascorbate, termed scurvy, has long been associated with increased susceptibility to infections. How ascorbate affects the immune system at the cellular and molecular levels remained unclear. From a micronutrient analysis, we identified ascorbate as a potent enhancer for antibody response by facilitating the IL-21/STAT3-dependent plasma cell differentiation in mouse and human B cells. The effect of ascorbate is unique as other antioxidants failed to promote plasma cell differentiation. Ascorbate is especially critical during early B cell activation by poising the cells to plasma cell lineage without affecting the proximal IL-21/STAT3 signaling and the overall transcriptome. As a cofactor for epigenetic enzymes, ascorbate facilitates TET2/3-mediated DNA modification and demethylation of multiple elements at the Prdm1 locus. DNA demethylation augments STAT3 association at the Prdm1 promoter and a downstream enhancer, thus ensuring efficient gene expression and plasma cell differentiation. The results suggest that an adequate level of ascorbate is required for antibody response and highlight how micronutrients may regulate the activity of epigenetic enzymes to regulate gene expression. Our findings imply that epigenetic enzymes can function as sensors to gauge the availability of metabolites and influence cell fate decisions.


Assuntos
Ácido Ascórbico , Vitaminas , Animais , Ácido Ascórbico/farmacologia , Diferenciação Celular , Epigênese Genética , Epigenômica , Humanos , Camundongos
12.
J Vis Exp ; (185)2022 07 27.
Artigo em Inglês | MEDLINE | ID: mdl-35969083

RESUMO

Heart disease is the leading cause of morbidity and mortality worldwide. Due to their low cost, ease of handling, and abundance of transgenic strains, rodents have become essential models for cardiovascular research. However, spontaneous lethal cardiac arrhythmias that often cause mortality in heart disease patients are rare in rodent models of heart disease. This is primarily due to the species differences in cardiac electrical properties between human and rodents and poses a challenge to the study of cardiac arrhythmias using rodents. This protocol describes an approach to enable efficient transgene expression in mouse and rat ventricular myocardium using echocardiography-guided intramuscular injections of recombinant virus (adenovirus and adeno-associated virus). This work also outlines a method to enable reliable assessment of cardiac susceptibility to arrhythmias using isolated, Langendorff-perfused mouse and rat hearts with both adrenergic and programmed electrical stimulations. These techniques are critical for studying heart rhythm disorders associated with adverse cardiac remodeling after injuries, such as myocardial infarction.


Assuntos
Arritmias Cardíacas , Transgenes , Animais , Animais Geneticamente Modificados , Arritmias Cardíacas/fisiopatologia , Modelos Animais de Doenças , Coração , Humanos , Camundongos , Miocárdio/metabolismo , Ratos
13.
Nat Immunol ; 23(3): 431-445, 2022 03.
Artigo em Inglês | MEDLINE | ID: mdl-35228694

RESUMO

Chronic inflammation triggers compensatory immunosuppression to stop inflammation and minimize tissue damage. Studies have demonstrated that endoplasmic reticulum (ER) stress augments the suppressive phenotypes of immune cells; however, the molecular mechanisms underpinning this process and how it links to the metabolic reprogramming of immunosuppressive macrophages remain elusive. In the present study, we report that the helper T cell 2 cytokine interleukin-4 and the tumor microenvironment increase the activity of a protein kinase RNA-like ER kinase (PERK)-signaling cascade in macrophages and promote immunosuppressive M2 activation and proliferation. Loss of PERK signaling impeded mitochondrial respiration and lipid oxidation critical for M2 macrophages. PERK activation mediated the upregulation of phosphoserine aminotransferase 1 (PSAT1) and serine biosynthesis via the downstream transcription factor ATF-4. Increased serine biosynthesis resulted in enhanced mitochondrial function and α-ketoglutarate production required for JMJD3-dependent epigenetic modification. Inhibition of PERK suppressed macrophage immunosuppressive activity and could enhance the efficacy of immune checkpoint programmed cell death protein 1 inhibition in melanoma. Our findings delineate a previously undescribed connection between PERK signaling and PSAT1-mediated serine metabolism critical for promoting immunosuppressive function in M2 macrophages.


Assuntos
Estresse do Retículo Endoplasmático , eIF-2 Quinase , Estresse do Retículo Endoplasmático/genética , Macrófagos/metabolismo , Transdução de Sinais , Resposta a Proteínas não Dobradas , eIF-2 Quinase/genética , eIF-2 Quinase/metabolismo
14.
Annu Rev Immunol ; 40: 387-411, 2022 04 26.
Artigo em Inglês | MEDLINE | ID: mdl-35119910

RESUMO

Cell identity and function largely rely on the programming of transcriptomes during development and differentiation. Signature gene expression programs are orchestrated by regulatory circuits consisting of cis-acting promoters and enhancers, which respond to a plethora of cues via the action of transcription factors. In turn, transcription factors direct epigenetic modifications to revise chromatin landscapes, and drive contacts between distal promoter-enhancer combinations. In immune cells, regulatory circuits for effector genes are especially complex and flexible, utilizing distinct sets of transcription factors and enhancers, depending on the cues each cell type receives during an infection, after sensing cellular damage, or upon encountering a tumor. Here, we review major players in the coordination of gene regulatory programs within innate and adaptive immune cells, as well as integrative omics approaches that can be leveraged to decipher their underlying circuitry.


Assuntos
Cromatina , Redes Reguladoras de Genes , Animais , Regulação da Expressão Gênica , Humanos , Regiões Promotoras Genéticas , Fatores de Transcrição/genética
15.
J Nucl Cardiol ; 29(6): 3057-3068, 2022 12.
Artigo em Inglês | MEDLINE | ID: mdl-34820771

RESUMO

AIMS: This study aimed to evaluate markers of systemic as well as imaging markers of inflammation in the ascending aorta, bone marrow, and spleen measured by 18F-FDG PET/CT, in HIV+ patients at baseline and following therapy with rosuvastatin. METHODS AND RESULTS: Of the 35 HIV+ patients enrolled, 17 were randomized to treatment with 10 mg/day rosuvastatin and 18 to usual care for 6 months. An HIV- control cohort was selected for baseline comparison of serum inflammatory markers and monocyte markers of inflammation. 18F-FDG-PET/CT imaging of bone marrow, spleen, and thoracic aorta was performed in the HIV+ cohort at baseline and 6 months. While CD14++CD16- and CCR2 expressions were reduced, serum levels of IL-7, IL-8, and MCP-1 were elevated in the HIV+ population compared to the controls. There was a significant drop in FDG uptake in the bone marrow (TBRmax), spleen (SUVmax) and thoracic aortic (TBRmax) in the statin-treated group compared to the control group (bone marrow: - 10.3 ± 16.9% versus 5.0 ± 18.9%, p = .0262; spleen: - 9.8 ± 20.3% versus 11.3 ± 28.8%, p = .0497; thoracic aorta: - 19.1 ± 24.2% versus 4.3 ± 15.4%, p = .003). CONCLUSIONS: HIV+ patients had significantly markers of systemic inflammation including monocyte activation. Treatment with low-dose rosuvastatin in the HIV+ cohort significantly reduced bone marrow, spleen and thoracic aortic FDG uptake.


Assuntos
Fluordesoxiglucose F18 , Infecções por HIV , Humanos , Rosuvastatina Cálcica/farmacologia , Rosuvastatina Cálcica/uso terapêutico , Tomografia por Emissão de Pósitrons combinada à Tomografia Computadorizada/métodos , Projetos Piloto , Infecções por HIV/complicações , Infecções por HIV/diagnóstico por imagem , Infecções por HIV/tratamento farmacológico , Inflamação/diagnóstico por imagem , Inflamação/tratamento farmacológico , Biomarcadores , Anti-Inflamatórios/uso terapêutico , Compostos Radiofarmacêuticos
16.
Immunol Rev ; 305(1): 152-164, 2022 01.
Artigo em Inglês | MEDLINE | ID: mdl-34820863

RESUMO

Micronutrients are essential small molecules required by organisms in minute quantity for survival. For instance, vitamins and minerals, the two major categories of micronutrients, are central for biological processes such as metabolism, cell replication, differentiation, and immune response. Studies estimated that around two billion humans worldwide suffer from micronutrient deficiencies, also known as "hidden hunger," linked to weakened immune responses. While micronutrients affect the immune system at multiple levels, recent studies showed that micronutrients potentially impact the differentiation and function of immune cells as cofactors for epigenetic enzymes, including the 2-oxoglutarate-dependent dioxygenase (2OGDD) family involved in histone and DNA demethylation. Here, we will first provide an overview of the role of DNA methylation in T cells and B cells, followed by the micronutrients ascorbate (vitamin C) and iron, two critical cofactors for 2OGDD. We will discuss the emerging evidence of these micronutrients could regulate adaptive immune response by influencing epigenetic remodeling.


Assuntos
Epigênese Genética , Micronutrientes , Humanos , Imunidade/genética , Micronutrientes/metabolismo , Minerais/metabolismo , Vitaminas
17.
Sci Rep ; 11(1): 17722, 2021 09 06.
Artigo em Inglês | MEDLINE | ID: mdl-34489488

RESUMO

Wnt/ß-catenin signaling is activated in the heart after myocardial infarction (MI). This study aims to investigate if ß-catenin deletion affects post-MI ion channel gene alterations and ventricular tachycardias (VT). MI was induced by permanent ligation of left anterior descending artery in wild-type (WT) and cardiomyocyte-specific ß-catenin knockout (KO) mice. KO mice showed reduced susceptibility to VT (18% vs. 77% in WT) at 8 weeks after MI, associated with reduced scar size and attenuated chamber dilation. qPCR analyses of both myocardial tissues and purified cardiomyocytes demonstrated upregulation of Wnt pathway genes in border and infarct regions after MI, including Wnt ligands (such as Wnt4) and receptors (such as Fzd1 and Fzd2). At 1 week after MI, cardiac sodium channel gene (Scn5a) transcript was reduced in WT but not in KO hearts, consistent with previous studies showing Scn5a inhibition by Wnt/ß-catenin signaling. At 8 weeks after MI when Wnt genes have declined, Scn5a returned to near sham levels and K+ channel gene downregulations were not different between WT and KO mice. This study demonstrated that VT susceptibility in the chronic phase after MI is reduced in mice with cardiomyocyte-specific ß-catenin deletion primarily through attenuated structural remodeling, but not ion channel gene alterations.


Assuntos
Arritmias Cardíacas/metabolismo , Coração/fisiopatologia , Infarto do Miocárdio/metabolismo , Miocárdio/metabolismo , Miócitos Cardíacos/metabolismo , beta Catenina/metabolismo , Animais , Arritmias Cardíacas/genética , Arritmias Cardíacas/fisiopatologia , Modelos Animais de Doenças , Camundongos , Camundongos Knockout , Infarto do Miocárdio/genética , Infarto do Miocárdio/fisiopatologia , Remodelação Ventricular/fisiologia , beta Catenina/genética
18.
Genome Biol ; 22(1): 186, 2021 06 22.
Artigo em Inglês | MEDLINE | ID: mdl-34158086

RESUMO

BACKGROUND: TET enzymes mediate DNA demethylation by oxidizing 5-methylcytosine (5mC) in DNA to 5-hydroxymethylcytosine (5hmC), 5-formylcytosine (5fC), and 5-carboxylcytosine (5caC). Since these oxidized methylcytosines (oxi-mCs) are not recognized by the maintenance methyltransferase DNMT1, DNA demethylation can occur through "passive," replication-dependent dilution when cells divide. A distinct, replication-independent ("active") mechanism of DNA demethylation involves excision of 5fC and 5caC by the DNA repair enzyme thymine DNA glycosylase (TDG), followed by base excision repair. RESULTS: Here by analyzing inducible gene-disrupted mice, we show that DNA demethylation during primary T cell differentiation occurs mainly through passive replication-dependent dilution of all three oxi-mCs, with only a negligible contribution from TDG. In addition, by pyridine borane sequencing (PB-seq), a simple recently developed method that directly maps 5fC/5caC at single-base resolution, we detect the accumulation of 5fC/5caC in TDG-deleted T cells. We also quantify the occurrence of concordant demethylation within and near enhancer regions in the Il4 locus. In an independent system that does not involve cell division, macrophages treated with liposaccharide accumulate 5hmC at enhancers and show altered gene expression without DNA demethylation; loss of TET enzymes disrupts gene expression, but loss of TDG has no effect. We also observe that mice with long-term (1 year) deletion of Tdg are healthy and show normal survival and hematopoiesis. CONCLUSIONS: We have quantified the relative contributions of TET and TDG to cell differentiation and DNA demethylation at representative loci in proliferating T cells. We find that TET enzymes regulate T cell differentiation and DNA demethylation primarily through passive dilution of oxi-mCs. In contrast, while we observe a low level of active, replication-independent DNA demethylation mediated by TDG, this process does not appear to be essential for immune cell activation or differentiation.


Assuntos
Metilação de DNA , Proteínas de Ligação a DNA/genética , Dioxigenases/genética , Macrófagos/enzimologia , Linfócitos T/enzimologia , Timina DNA Glicosilase/genética , 5-Metilcitosina/análogos & derivados , 5-Metilcitosina/metabolismo , Animais , Diferenciação Celular , Proliferação de Células , Citosina/análogos & derivados , Citosina/metabolismo , DNA/genética , DNA/metabolismo , Proteínas de Ligação a DNA/deficiência , Dioxigenases/deficiência , Elementos Facilitadores Genéticos , Expressão Gênica , Loci Gênicos , Hematopoese/genética , Interleucina-4/genética , Interleucina-4/metabolismo , Isoenzimas/genética , Isoenzimas/metabolismo , Lipopolissacarídeos/farmacologia , Longevidade/genética , Macrófagos/citologia , Macrófagos/efeitos dos fármacos , Macrófagos/imunologia , Camundongos , Camundongos Knockout , Linfócitos T/citologia , Linfócitos T/imunologia , Timina DNA Glicosilase/deficiência
19.
J Patient Exp ; 8: 23743735211007700, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34179422

RESUMO

The purpose of this study was to explore patient perceptions of primary care providers and their offices relative to their physician's philosophy (medical degree [MD] vs doctorate in osteopathic medicine [DO]), specialty (internal medicine vs family medicine), US region, and gender (male vs female). Using the Healthgrades website, the average satisfaction rating for the physician, office parameters, and wait time were collected and analyzed for 1267 physicians. We found female doctors tended to have lower ratings in the Midwest, and staff friendliness of female physicians were rated lower in the northwest. In the northeast, male and female MDs were rated more highly than DOs. Wait times varied regionally, with northeast and northwest regions having the shortest wait times. Overall satisfaction was generally high for most physicians. Regional differences in perception of a physician based on gender or degree may have roots in local culture, including proximity to a DO school, comfort with female physicians, and expectations for waiting times.

20.
Chest ; 160(2): 446-453, 2021 08.
Artigo em Inglês | MEDLINE | ID: mdl-33667494

RESUMO

BACKGROUND: Survivors of community-acquired pneumonia (CAP) are at increased risk of cardiovascular disease, cognitive and functional decline, and death, but the mechanisms remain unknown. RESEARCH QUESTION: Do CAP survivors have evidence of increased inflammatory activity in their lung parenchyma on 2-deoxy-2-[18F]fluoro-d-glucose (18FDG)-PET/CT imaging after clinical resolution of infection? STUDY DESIGN AND METHODS: We obtained 18FDG-PET/CT scans from 22 CAP survivors during their hospitalization with pneumonia (acute CAP) and 30 to 45 days after hospital discharge (post-CAP). In each set of scans, we assessed the lungs for foci of increased 18FDG uptake by visual interpretation and by total pulmonary glycolytic activity (tPGA), a background-corrected measure of total metabolic activity (as measured by 18FDG uptake). We also measured, post-CAP, the glycolytic activity of CAP survivor lung areas with volumes similar to the areas in 28 matched historical control subjects without pneumonia. RESULTS: Overall, 68% of CAP survivors (95% CI, 45%-85%) had distinct residual areas of increased 18FDG uptake in their post-CAP studies. tPGA decreased from 821.5 (SD, 1,140.2) in the acute CAP period to 80.0 (SD, 81.4) in the post-CAP period (P = .006). The tPGA post-CAP was significantly higher than that in lung areas of similar volume in control subjects (80.0 [SD, 81.4] vs -19.4 [SD, 5.9]; P < .001). INTERPRETATION: An important proportion of CAP survivors have persistent pulmonary foci of increased inflammatory activity beyond resolution of their infection. As inflammation contributes to cardiovascular disease, cognitive decline, functional waning, and mortality risk in the general population, this finding provides a plausible mechanism for the increased morbidity and mortality that have been observed post-CAP.


Assuntos
Infecções Comunitárias Adquiridas/diagnóstico por imagem , Pneumonia/diagnóstico por imagem , Tomografia por Emissão de Pósitrons combinada à Tomografia Computadorizada , Idoso , Infecções Comunitárias Adquiridas/terapia , Progressão da Doença , Feminino , Fluordesoxiglucose F18 , Humanos , Masculino , Pneumonia/terapia , Compostos Radiofarmacêuticos , Índice de Gravidade de Doença
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...