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1.
Cell ; 174(6): 1436-1449.e20, 2018 09 06.
Artigo em Inglês | MEDLINE | ID: mdl-30146163

RESUMO

Synaptic vesicle and active zone proteins are required for synaptogenesis. The molecular mechanisms for coordinated synthesis of these proteins are not understood. Using forward genetic screens, we identified the conserved THO nuclear export complex (THOC) as an important regulator of presynapse development in C. elegans dopaminergic neurons. In THOC mutants, synaptic messenger RNAs are retained in the nucleus, resulting in dramatic decrease of synaptic protein expression, near complete loss of synapses, and compromised dopamine function. CRE binding protein (CREB) interacts with THOC to mark synaptic transcripts for efficient nuclear export. Deletion of Thoc5, a THOC subunit, in mouse dopaminergic neurons causes severe defects in synapse maintenance and subsequent neuronal death in the substantia nigra compacta. These cellular defects lead to abrogated dopamine release, ataxia, and animal death. Together, our results argue that nuclear export mechanisms can select specific mRNAs and be a rate-limiting step for neuronal differentiation and survival.


Assuntos
Proteínas de Caenorhabditis elegans/genética , Neurônios Dopaminérgicos/metabolismo , Proteínas Nucleares/genética , Sinapses/metabolismo , Transporte Ativo do Núcleo Celular , Esclerose Lateral Amiotrófica/metabolismo , Esclerose Lateral Amiotrófica/patologia , Animais , Caenorhabditis elegans , Proteínas de Caenorhabditis elegans/metabolismo , Sinalização do Cálcio , Núcleo Celular/metabolismo , Proteína de Ligação ao Elemento de Resposta ao AMP Cíclico/genética , Proteína de Ligação ao Elemento de Resposta ao AMP Cíclico/metabolismo , Feminino , Humanos , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Mutagênese , Mutação de Sentido Incorreto , Proteínas Nucleares/deficiência , Proteínas Nucleares/metabolismo , Subunidades Proteicas/deficiência , Subunidades Proteicas/genética , Subunidades Proteicas/metabolismo
2.
Physiol Rev ; 104(2): 765-834, 2024 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-37971403

RESUMO

Phosphodiesterases (PDEs) are a superfamily of enzymes that hydrolyze cyclic nucleotides, including cyclic adenosine monophosphate (cAMP) and cyclic guanosine monophosphate (cGMP). Both cyclic nucleotides are critical secondary messengers in the neurohormonal regulation in the cardiovascular system. PDEs precisely control spatiotemporal subcellular distribution of cyclic nucleotides in a cell- and tissue-specific manner, playing critical roles in physiological responses to hormone stimulation in the heart and vessels. Dysregulation of PDEs has been linked to the development of several cardiovascular diseases, such as hypertension, aneurysm, atherosclerosis, arrhythmia, and heart failure. Targeting these enzymes has been proven effective in treating cardiovascular diseases and is an attractive and promising strategy for the development of new drugs. In this review, we discuss the current understanding of the complex regulation of PDE isoforms in cardiovascular function, highlighting the divergent and even opposing roles of PDE isoforms in different pathogenesis.


Assuntos
Doenças Cardiovasculares , Dietilestilbestrol/análogos & derivados , Diester Fosfórico Hidrolases , Humanos , Inibidores de Fosfodiesterase/uso terapêutico , AMP Cíclico , GMP Cíclico , Isoformas de Proteínas
3.
PLoS Genet ; 20(3): e1011196, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38466721

RESUMO

Hematophagous mosquitoes require vertebrate blood for their reproductive cycles, making them effective vectors for transmitting dangerous human diseases. Thus, high-intensity metabolism is needed to support reproductive events of female mosquitoes. However, the regulatory mechanism linking metabolism and reproduction in mosquitoes remains largely unclear. In this study, we found that the expression of estrogen-related receptor (ERR), a nuclear receptor, is activated by the direct binding of 20-hydroxyecdysone (20E) and ecdysone receptor (EcR) to the ecdysone response element (EcRE) in the ERR promoter region during the gonadotropic cycle of Aedes aegypti (named AaERR). RNA interference (RNAi) of AaERR in female mosquitoes led to delayed development of ovaries. mRNA abundance of genes encoding key enzymes involved in carbohydrate metabolism (CM)-glucose-6-phosphate isomerase (GPI) and pyruvate kinase (PYK)-was significantly decreased in AaERR knockdown mosquitoes, while the levels of metabolites, such as glycogen, glucose, and trehalose, were elevated. The expression of fatty acid synthase (FAS) was notably downregulated, and lipid accumulation was reduced in response to AaERR depletion. Dual luciferase reporter assays and electrophoretic mobility shift assays (EMSA) determined that AaERR directly activated the expression of metabolic genes, such as GPI, PYK, and FAS, by binding to the corresponding AaERR-responsive motif in the promoter region of these genes. Our results have revealed an important role of AaERR in the regulation of metabolism during mosquito reproduction and offer a novel target for mosquito control.


Assuntos
Aedes , Receptores de Esteroides , Animais , Feminino , Humanos , Aedes/genética , Aedes/metabolismo , Ecdisona/metabolismo , Mosquitos Vetores/genética , Receptores Citoplasmáticos e Nucleares/genética , Receptores Citoplasmáticos e Nucleares/metabolismo , Homeostase/genética , Proteínas de Insetos/genética , Proteínas de Insetos/metabolismo
4.
Proc Natl Acad Sci U S A ; 120(10): e2215916120, 2023 03 07.
Artigo em Inglês | MEDLINE | ID: mdl-36853938

RESUMO

G protein-coupled receptors (GPCRs) represent the largest group of membrane receptors for transmembrane signal transduction. Ligand-induced activation of GPCRs triggers G protein activation followed by various signaling cascades. Understanding the structural and energetic determinants of ligand binding to GPCRs and GPCRs to G proteins is crucial to the design of pharmacological treatments targeting specific conformations of these proteins to precisely control their signaling properties. In this study, we focused on interactions of a prototypical GPCR, beta-2 adrenergic receptor (ß2AR), with its endogenous agonist, norepinephrine (NE), and the stimulatory G protein (Gs). Using molecular dynamics (MD) simulations, we demonstrated the stabilization of cationic NE, NE(+), binding to ß2AR by Gs protein recruitment, in line with experimental observations. We also captured the partial dissociation of the ligand from ß2AR and the conformational interconversions of Gs between closed and open conformations in the NE(+)-ß2AR-Gs ternary complex while it is still bound to the receptor. The variation of NE(+) binding poses was found to alter Gs α subunit (Gsα) conformational transitions. Our simulations showed that the interdomain movement and the stacking of Gsα α1 and α5 helices are significant for increasing the distance between the Gsα and ß2AR, which may indicate a partial dissociation of Gsα The distance increase commences when Gsα is predominantly in an open state and can be triggered by the intracellular loop 3 (ICL3) of ß2AR interacting with Gsα, causing conformational changes of the α5 helix. Our results help explain molecular mechanisms of ligand and GPCR-mediated modulation of G protein activation.


Assuntos
Subunidades alfa Gs de Proteínas de Ligação ao GTP , Receptores Adrenérgicos beta 2 , Ligantes , Transdução de Sinais , Simulação de Dinâmica Molecular , Norepinefrina
5.
Proc Natl Acad Sci U S A ; 120(39): e2302878120, 2023 09 26.
Artigo em Inglês | MEDLINE | ID: mdl-37722058

RESUMO

Although tumor-intrinsic fatty acid ß-oxidation (FAO) is implicated in multiple aspects of tumorigenesis and progression, the impact of this metabolic pathway on cancer cell susceptibility to immunotherapy remains unknown. Here, we report that cytotoxicity of killer T cells induces activation of FAO and upregulation of carnitine palmitoyltransferase 1A (CPT1A), the rate-limiting enzyme of FAO in cancer cells. The repression of CPT1A activity or expression renders cancer cells more susceptible to destruction by cytotoxic T lymphocytes. Our mechanistic studies reveal that FAO deficiency abrogates the prosurvival signaling in cancer cells under immune cytolytic stress. Furthermore, we identify T cell-derived IFN-γ as a major factor responsible for induction of CPT1A and FAO in an AMPK-dependent manner, indicating a dynamic interplay between immune effector cells and tumor targets. While cancer growth in the absence of CPT1A remains largely unaffected, established tumors upon FAO inhibition become significantly more responsive to cellular immunotherapies including chimeric antigen receptor-engineered human T cells. Together, these findings uncover a mode of cancer resistance and immune editing that can facilitate immune escape and limit the benefits of immunotherapies.


Assuntos
Carnitina O-Palmitoiltransferase , Neoplasias , Humanos , Carnitina O-Palmitoiltransferase/genética , Citotoxicidade Imunológica , Ácidos Graxos , Metabolismo dos Lipídeos , Neoplasias/terapia , Linfócitos T Citotóxicos
6.
Proc Natl Acad Sci U S A ; 120(45): e2307094120, 2023 Nov 07.
Artigo em Inglês | MEDLINE | ID: mdl-37922327

RESUMO

Bone metastasis is a frequent and incurable consequence of advanced prostate cancer (PC). An interplay between disseminated tumor cells and heterogeneous bone resident cells in the metastatic niche initiates this process. Melanoma differentiation associated gene-9 (mda-9/Syntenin/syndecan binding protein) is a prometastatic gene expressed in multiple organs, including bone marrow-derived mesenchymal stromal cells (BM-MSCs), under both physiological and pathological conditions. We demonstrate that PDGF-AA secreted by tumor cells induces CXCL5 expression in BM-MSCs by suppressing MDA-9-dependent YAP/MST signaling. CXCL5-derived tumor cell proliferation and immune suppression are consequences of the MDA-9/CXCL5 signaling axis, promoting PC disease progression. mda-9 knockout tumor cells express less PDGF-AA and do not develop bone metastases. Our data document a previously undefined role of MDA-9/Syntenin in the tumor and microenvironment in regulating PC bone metastasis. This study provides a framework for translational strategies to ameliorate health complications and morbidity associated with advanced PC.


Assuntos
Neoplasias Ósseas , Melanoma , Neoplasias da Próstata , Masculino , Humanos , Sinteninas/genética , Sinteninas/metabolismo , Melanoma/metabolismo , Neoplasias da Próstata/genética , Transdução de Sinais/genética , Neoplasias Ósseas/genética , Linhagem Celular Tumoral , Microambiente Tumoral , Metástase Neoplásica
7.
Genet Epidemiol ; 48(3): 103-113, 2024 04.
Artigo em Inglês | MEDLINE | ID: mdl-38317324

RESUMO

Genome-wide association studies (GWAS) have led to rapid growth in detecting genetic variants associated with various phenotypes. Owing to a great number of publicly accessible GWAS summary statistics, and the difficulty in obtaining individual-level genotype data, many existing gene-based association tests have been adapted to require only GWAS summary statistics rather than individual-level data. However, these association tests are restricted to unrelated individuals and thus do not apply to family samples directly. Moreover, due to its flexibility and effectiveness, the linear mixed model has been increasingly utilized in GWAS to handle correlated data, such as family samples. However, it remains unknown how to perform gene-based association tests in family samples using the GWAS summary statistics estimated from the linear mixed model. In this study, we show that, when family size is negligible compared to the total sample size, the diagonal block structure of the kinship matrix makes it possible to approximate the correlation matrix of marginal Z scores by linkage disequilibrium matrix. Based on this result, current methods utilizing summary statistics for unrelated individuals can be directly applied to family data without any modifications. Our simulation results demonstrate that this proposed strategy controls the type 1 error rate well in various situations. Finally, we exemplify the usefulness of the proposed approach with a dental caries GWAS data set.


Assuntos
Cárie Dentária , Estudo de Associação Genômica Ampla , Humanos , Estudo de Associação Genômica Ampla/métodos , Polimorfismo de Nucleotídeo Único , Modelos Genéticos , Fenótipo
8.
Lancet ; 403(10434): 1341-1350, 2024 Apr 06.
Artigo em Inglês | MEDLINE | ID: mdl-38521086

RESUMO

BACKGROUND: Pembrolizumab has shown efficacy in persistent, recurrent, or metastatic cervical cancer. The effect of chemoradiotherapy might be enhanced by immunotherapy. In this phase 3 trial, we assessed the efficacy and safety of adding pembrolizumab to chemoradiotherapy in locally advanced cervical cancer. METHODS: In this randomised, double-blind, placebo-controlled, phase 3 ENGOT-cx11/GOG-3047/KEYNOTE-A18 clinical trial, adults (age ≥18 years) at 176 medical centres in 30 countries with newly diagnosed, high-risk, locally advanced cervical cancer were randomly assigned (1:1) using an interactive voice-response system with integrated web response to receive 5 cycles of pembrolizumab (200 mg) or placebo every 3 weeks plus chemoradiotherapy, followed by 15 cycles of pembrolizumab (400 mg) or placebo every 6 weeks. Randomisation was stratified by planned external beam radiotherapy type (intensity-modulated radiotherapy or volumetric-modulated arc therapy vs non-intensity-modulated radiotherapy or non-volumetric-modulated arc therapy), cervical cancer stage at screening (International Federation of Gynecology and Obstetrics 2014 stage IB2-IIB node positive vs stage III-IVA), and planned total radiotherapy (external beam radiotherapy plus brachytherapy) dose (<70 Gy vs ≥70 Gy equivalent dose in 2 Gy fractions). Primary endpoints were progression-free survival per Response Evaluation Criteria in Solid Tumours version 1.1-by investigator or by histopathologic confirmation of suspected disease progression-and overall survival. Primary analysis was conducted in the intention-to-treat population, which included all randomly allocated participants. Safety was assessed in the as-treated population, which included all randomly allocated patients who received at least one dose of study treatment. This study is registered with ClinicalTrials.gov, NCT04221945, and is closed to new participants. FINDINGS: Between June 9, 2020, and Dec 15, 2022, 1060 participants were randomly assigned to treatment, with 529 assigned to the pembrolizumab-chemoradiotherapy group and 531 to the placebo-chemoradiotherapy group. At data cutoff (Jan 9, 2023), median follow-up was 17·9 months (IQR 11·3-22·3) in both treatment groups. Median progression-free survival was not reached in either group; rates at 24 months were 68% in the pembrolizumab-chemoradiotherapy group versus 57% in the placebo-chemoradiotherapy group. The hazard ratio (HR) for disease progression or death was 0·70 (95% CI 0·55-0·89, p=0·0020), meeting the protocol-specified primary objective. Overall survival at 24 months was 87% in the pembrolizumab-chemoradiotherapy group and 81% in the placebo-chemoradiotherapy group (information fraction 42·9%). The HR for death was 0·73 (0·49-1·07); these data have not crossed the boundary of statistical significance. Grade 3 or higher adverse event rates were 75% in the pembrolizumab-chemoradiotherapy group and 69% in the placebo-chemoradiotherapy group. INTERPRETATION: Pembrolizumab plus chemoradiotherapy significantly improved progression-free survival in patients with newly diagnosed, high-risk, locally advanced cervical cancer. FUNDING: Merck Sharp & Dohme, a subsidiary of Merck & Co (MSD).


Assuntos
Neoplasias do Colo do Útero , Adulto , Feminino , Humanos , Adolescente , Neoplasias do Colo do Útero/terapia , Anticorpos Monoclonais Humanizados/efeitos adversos , Quimiorradioterapia , Progressão da Doença , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Método Duplo-Cego
9.
Lancet ; 404(10460): 1321-1332, 2024 Oct 05.
Artigo em Inglês | MEDLINE | ID: mdl-39288779

RESUMO

BACKGROUND: At the first interim analysis of the phase 3 ENGOT-cx11/GOG-3047/KEYNOTE-A18 study, the addition of pembrolizumab to chemoradiotherapy provided a statistically significant and clinically meaningful improvement in progression-free survival in patients with locally advanced cervical cancer. We report the overall survival results from the second interim analysis of this study. METHODS: Eligible patients with newly diagnosed, high-risk (FIGO 2014 stage IB2-IIB with node-positive disease or stage III-IVA regardless of nodal status), locally advanced, histologically confirmed, squamous cell carcinoma, adenocarcinoma, or adenosquamous cervical cancer were randomly assigned 1:1 to receive five cycles of pembrolizumab (200 mg) or placebo every 3 weeks with concurrent chemoradiotherapy, followed by 15 cycles of pembrolizumab (400 mg) or placebo every 6 weeks. Pembrolizumab or placebo and cisplatin were administered intravenously. Patients were stratified at randomisation by planned external beam radiotherapy type (intensity-modulated radiotherapy [IMRT] or volumetric-modulated arc therapy [VMAT] vs non-IMRT or non-VMAT), cervical cancer stage at screening (FIGO 2014 stage IB2-IIB node positive vs III-IVA), and planned total radiotherapy (external beam radiotherapy plus brachytherapy) dose (<70 Gy vs ≥70 Gy [equivalent dose of 2 Gy]). Primary endpoints were progression-free survival per RECIST 1.1 by investigator or by histopathological confirmation of suspected disease progression and overall survival defined as the time from randomisation to death due to any cause. Safety was a secondary endpoint. FINDINGS: Between June 9, 2020, and Dec 15, 2022, 1060 patients at 176 sites in 30 countries across Asia, Australia, Europe, North America, and South America were randomly assigned to treatment, with 529 patients in the pembrolizumab-chemoradiotherapy group and 531 patients in the placebo-chemoradiotherapy group. At the protocol-specified second interim analysis (data cutoff Jan 8, 2024), median follow-up was 29·9 months (IQR 23·3-34·3). Median overall survival was not reached in either group; 36-month overall survival was 82·6% (95% CI 78·4-86·1) in the pembrolizumab-chemoradiotherapy group and 74·8% (70·1-78·8) in the placebo-chemoradiotherapy group. The hazard ratio for death was 0·67 (95% CI 0·50-0·90; p=0·0040), meeting the protocol-specified primary objective. 413 (78%) of 528 patients in the pembrolizumab-chemoradiotherapy group and 371 (70%) of 530 in the placebo-chemoradiotherapy group had a grade 3 or higher adverse event, with anaemia, white blood cell count decreased, and neutrophil count decreased being the most common adverse events. Potentially immune-mediated adverse events occurred in 206 (39%) of 528 patients in the pembrolizumab-chemoradiotherapy group and 90 (17%) of 530 patients in the placebo-chemoradiotherapy group. This study is registered with ClinicalTrials.gov, NCT04221945. INTERPRETATION: Pembrolizumab plus chemoradiotherapy significantly improved overall survival in patients with locally advanced cervical cancer These data, together with results from the first interim analysis, support this immuno-chemoradiotherapy strategy as a new standard of care for this population. FUNDING: Merck Sharp & Dohme, a subsidiary of Merck & Co.


Assuntos
Anticorpos Monoclonais Humanizados , Quimiorradioterapia , Neoplasias do Colo do Útero , Adulto , Idoso , Feminino , Humanos , Pessoa de Meia-Idade , Adenocarcinoma/tratamento farmacológico , Adenocarcinoma/mortalidade , Adenocarcinoma/radioterapia , Anticorpos Monoclonais Humanizados/efeitos adversos , Anticorpos Monoclonais Humanizados/uso terapêutico , Antineoplásicos Imunológicos/uso terapêutico , Antineoplásicos Imunológicos/efeitos adversos , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Carcinoma Adenoescamoso/tratamento farmacológico , Carcinoma Adenoescamoso/mortalidade , Carcinoma Adenoescamoso/radioterapia , Carcinoma de Células Escamosas/tratamento farmacológico , Carcinoma de Células Escamosas/mortalidade , Carcinoma de Células Escamosas/radioterapia , Quimiorradioterapia/métodos , Método Duplo-Cego , Estadiamento de Neoplasias , Intervalo Livre de Progressão , Neoplasias do Colo do Útero/tratamento farmacológico , Neoplasias do Colo do Útero/mortalidade , Neoplasias do Colo do Útero/radioterapia
10.
Nucleic Acids Res ; 51(3): 1087-1102, 2023 02 22.
Artigo em Inglês | MEDLINE | ID: mdl-36651270

RESUMO

Reactive oxygen species (ROS) are implicated in epithelial cell-state transition and deposition of extracellular matrix upon airway injury. Of the many cellular targets of ROS, oxidative DNA modification is a major driving signal. However, the role of oxidative DNA damage in modulation profibrotic processes has not been fully delineated. Herein, we report that oxidative DNA base lesions, 8-oxoG, complexed with 8-oxoguanine DNA glycosylase 1 (OGG1) functions as a pioneer factor, contributing to transcriptional reprogramming within airway epithelial cells. We show that TGFß1-induced ROS increased 8-oxoG levels in open chromatin, dynamically reconfigure the chromatin state. OGG1 complexed with 8-oxoG recruits transcription factors, including phosphorylated SMAD3, to pro-fibrotic gene promoters thereby facilitating gene activation. Moreover, 8-oxoG levels are elevated in lungs of mice subjected to TGFß1-induced injury. Pharmacologic targeting of OGG1 with the selective small molecule inhibitor of 8-oxoG binding, TH5487, abrogates fibrotic gene expression and remodeling in this model. Collectively, our study implicates that 8-oxoG substrate-specific binding by OGG1 is a central modulator of transcriptional regulation in response to tissue repair.


Assuntos
DNA Glicosilases , Guanina , Lesão Pulmonar , Animais , Camundongos , Cromatina , DNA/metabolismo , Dano ao DNA , DNA Glicosilases/metabolismo , Reparo do DNA , Espécies Reativas de Oxigênio/metabolismo , Ativação Transcricional , Guanina/análogos & derivados
11.
Proc Natl Acad Sci U S A ; 119(12): e2113645119, 2022 03 22.
Artigo em Inglês | MEDLINE | ID: mdl-35294287

RESUMO

Acute nociception is essential for survival by warning organisms against potential dangers, whereas tissue injury results in a nociceptive hypersensitivity state that is closely associated with debilitating disease conditions, such as chronic pain. Transient receptor potential (Trp) ion channels expressed in nociceptors detect noxious thermal and chemical stimuli to initiate acute nociception. The existing hypersensitivity model suggests that under tissue injury and inflammation, the same Trp channels in nociceptors are sensitized through transcriptional and posttranslational modulation, leading to nociceptive hypersensitivity. Unexpectedly and different from this model, we find that in Drosophila larvae, acute heat nociception and tissue injury-induced hypersensitivity involve distinct cellular and molecular mechanisms. Specifically, TrpA1-D in peripheral sensory neurons mediates acute heat nociception, whereas TrpA1-C in a cluster of larval brain neurons transduces the heat stimulus under the allodynia state. As a result, interfering with synaptic transmission of these brain neurons or genetic targeting of TrpA1-C blocks heat allodynia but not acute heat nociception. TrpA1-C and TrpA1-D are two splicing variants of TrpA1 channels and are coexpressed in these brain neurons. We further show that Gq-phospholipase C signaling, downstream of the proalgesic neuropeptide Tachykinin, differentially modulates these two TrpA1 isoforms in the brain neurons by selectively sensitizing heat responses of TrpA1-C but not TrpA1-D. Together, our studies provide evidence that nociception and noncaptive sensitization could be mediated by distinct sensory neurons and molecular sensors.


Assuntos
Nociceptividade , Canais de Potencial de Receptor Transitório , Animais , Drosophila/fisiologia , Neurônios , Nociceptividade/fisiologia , Nociceptores/fisiologia , Transdutores , Canais de Potencial de Receptor Transitório/genética
12.
Proc Natl Acad Sci U S A ; 119(36): e2206708119, 2022 09 06.
Artigo em Inglês | MEDLINE | ID: mdl-36044551

RESUMO

The sinoatrial node (SAN), the leading pacemaker region, generates electrical impulses that propagate throughout the heart. SAN dysfunction with bradyarrhythmia is well documented in heart failure (HF). However, the underlying mechanisms are not completely understood. Mitochondria are critical to cellular processes that determine the life or death of the cell. The release of Ca2+ from the ryanodine receptors 2 (RyR2) on the sarcoplasmic reticulum (SR) at mitochondria-SR microdomains serves as the critical communication to match energy production to meet metabolic demands. Therefore, we tested the hypothesis that alterations in the mitochondria-SR connectomics contribute to SAN dysfunction in HF. We took advantage of a mouse model of chronic pressure overload-induced HF by transverse aortic constriction (TAC) and a SAN-specific CRISPR-Cas9-mediated knockdown of mitofusin-2 (Mfn2), the mitochondria-SR tethering GTPase protein. TAC mice exhibited impaired cardiac function with HF, cardiac fibrosis, and profound SAN dysfunction. Ultrastructural imaging using electron microscope (EM) tomography revealed abnormal mitochondrial structure with increased mitochondria-SR distance. The expression of Mfn2 was significantly down-regulated and showed reduced colocalization with RyR2 in HF SAN cells. Indeed, SAN-specific Mfn2 knockdown led to alterations in the mitochondria-SR microdomains and SAN dysfunction. Finally, disruptions in the mitochondria-SR microdomains resulted in abnormal mitochondrial Ca2+ handling, alterations in localized protein kinase A (PKA) activity, and impaired mitochondrial function in HF SAN cells. The current study provides insights into the role of mitochondria-SR microdomains in SAN automaticity and possible therapeutic targets for SAN dysfunction in HF patients.


Assuntos
Conectoma , Insuficiência Cardíaca , Mitocôndrias Cardíacas , Retículo Sarcoplasmático , Síndrome do Nó Sinusal , Nó Sinoatrial , Animais , Insuficiência Cardíaca/patologia , Insuficiência Cardíaca/fisiopatologia , Camundongos , Mitocôndrias Cardíacas/ultraestrutura , Miócitos Cardíacos/metabolismo , Canal de Liberação de Cálcio do Receptor de Rianodina/genética , Canal de Liberação de Cálcio do Receptor de Rianodina/metabolismo , Retículo Sarcoplasmático/patologia , Síndrome do Nó Sinusal/patologia , Síndrome do Nó Sinusal/fisiopatologia , Nó Sinoatrial/fisiopatologia
13.
J Physiol ; 602(9): 2107-2126, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38568869

RESUMO

We are studying the mechanisms of H-reflex operant conditioning, a simple form of learning. Modelling studies in the literature and our previous data suggested that changes in the axon initial segment (AIS) might contribute. To explore this, we used blinded quantitative histological and immunohistochemical methods to study in adult rats the impact of H-reflex conditioning on the AIS of the spinal motoneuron that produces the reflex. Successful, but not unsuccessful, H-reflex up-conditioning was associated with greater AIS length and distance from soma; greater length correlated with greater H-reflex increase. Modelling studies in the literature suggest that these increases may increase motoneuron excitability, supporting the hypothesis that they may contribute to H-reflex increase. Up-conditioning did not affect AIS ankyrin G (AnkG) immunoreactivity (IR), p-p38 protein kinase IR, or GABAergic terminals. Successful, but not unsuccessful, H-reflex down-conditioning was associated with more GABAergic terminals on the AIS, weaker AnkG-IR, and stronger p-p38-IR. More GABAergic terminals and weaker AnkG-IR correlated with greater H-reflex decrease. These changes might potentially contribute to the positive shift in motoneuron firing threshold underlying H-reflex decrease; they are consistent with modelling suggesting that sodium channel change may be responsible. H-reflex down-conditioning did not affect AIS dimensions. This evidence that AIS plasticity is associated with and might contribute to H-reflex conditioning adds to evidence that motor learning involves both spinal and brain plasticity, and both neuronal and synaptic plasticity. AIS properties of spinal motoneurons are likely to reflect the combined influence of all the motor skills that share these motoneurons. KEY POINTS: Neuronal action potentials normally begin in the axon initial segment (AIS). AIS plasticity affects neuronal excitability in development and disease. Whether it does so in learning is unknown. Operant conditioning of a spinal reflex, a simple learning model, changes the rat spinal motoneuron AIS. Successful, but not unsuccessful, H-reflex up-conditioning is associated with greater AIS length and distance from soma. Successful, but not unsuccessful, down-conditioning is associated with more AIS GABAergic terminals, less ankyrin G, and more p-p38 protein kinase. The associations between AIS plasticity and successful H-reflex conditioning are consistent with those between AIS plasticity and functional changes in development and disease, and with those predicted by modelling studies in the literature. Motor learning changes neurons and synapses in spinal cord and brain. Because spinal motoneurons are the final common pathway for behaviour, their AIS properties probably reflect the combined impact of all the behaviours that use these motoneurons.


Assuntos
Segmento Inicial do Axônio , Reflexo H , Neurônios Motores , Ratos Sprague-Dawley , Animais , Neurônios Motores/fisiologia , Ratos , Masculino , Reflexo H/fisiologia , Segmento Inicial do Axônio/fisiologia , Aprendizagem/fisiologia , Medula Espinal/fisiologia , Medula Espinal/citologia , Axônios/fisiologia , Plasticidade Neuronal/fisiologia , Condicionamento Operante/fisiologia , Anquirinas/metabolismo
14.
J Biol Chem ; 299(7): 104915, 2023 07.
Artigo em Inglês | MEDLINE | ID: mdl-37315790

RESUMO

Biological functions of the highly conserved ubiquitin-like protein 5 (UBL5) are not well understood. In Caenorhabditis elegans, UBL5 is induced under mitochondrial stress to mount the mitochondrial unfolded protein response (UPR). However, the role of UBL5 in the more prevalent endoplasmic reticulum (ER) stress-UPR in the mammalian system is unknown. In the present work, we demonstrated that UBL5 was an ER stress-responsive protein, undergoing rapid depletion in mammalian cells and livers of mice. The ER stress-induced UBL5 depletion was mediated by proteasome-dependent yet ubiquitin-independent proteolysis. Activation of the protein kinase R-like ER kinase arm of the UPR was essential and sufficient for inducing UBL5 degradation. RNA-Seq analysis of UBL5-regulated transcriptome revealed that multiple death pathways were activated in UBL5-silenced cells. In agreement with this, UBL5 knockdown induced severe apoptosis in culture and suppressed tumorigenicity of cancer cells in vivo. Furthermore, overexpression of UBL5 protected specifically against ER stress-induced apoptosis. These results identify UBL5 as a physiologically relevant survival regulator that is proteolytically depleted by the UPR-protein kinase R-like ER kinase pathway, linking ER stress to cell death.


Assuntos
Morte Celular , Estresse do Retículo Endoplasmático , Ubiquitinas , eIF-2 Quinase , Animais , Camundongos , Apoptose , eIF-2 Quinase/metabolismo , Ubiquitinas/genética , Ubiquitinas/metabolismo , Resposta a Proteínas não Dobradas
15.
Am J Physiol Renal Physiol ; 326(2): F257-F264, 2024 02 01.
Artigo em Inglês | MEDLINE | ID: mdl-38031731

RESUMO

Renal artery stenosis (RAS) is a major cause of ischemic kidney disease, which is largely mediated by inflammation. Mapping the immune cell composition in ischemic kidneys might provide useful insight into the disease pathogenesis and uncover therapeutic targets. We used mass cytometry (CyTOF) to explore the single-cell composition in a unique data set of human kidneys nephrectomized due to chronic occlusive vascular disease (RAS, n = 3), relatively healthy donor kidneys (n = 6), and unaffected sections of kidneys with renal cell carcinoma (RCC, n = 3). Renal fibrosis and certain macrophage populations were also evaluated in renal sections. Cytobank analysis showed in RAS kidneys decreased cell populations expressing epithelial markers (CD45-/CD13+) and increased CD45+ inflammatory cells, whereas scattered tubular-progenitor-like cells (CD45-/CD133+/CD24+) increased compared with kidney donors. Macrophages switched to proinflammatory phenotypes in RAS, and the numbers of IL-10-producing dendritic cells (DC) were also lower. Compared with kidney donors, RAS kidneys had decreased overall DC populations but increased plasmacytoid DC. Furthermore, senescent active T cells (CD45+/CD28+/CD57+), aged neutrophils (CD45+/CD15+/CD24+/CD11c+), and regulatory B cells (CD45+/CD14-/CD24+/CD44+) were increased in RAS. RCC kidneys showed a distribution of cell phenotypes comparable with RAS but less pronounced, accompanied by an increase in CD34+, CD370+, CD103+, and CD11c+/CD103+ cells. Histologically, RAS kidneys showed significantly increased fibrosis and decreased CD163+/CD141+ cells. The single-cell platform CyTOF enables the detection of significant changes in renal cells, especially in subsets of immune cells in ischemic human kidneys. Endogenous pro-repair cell types in RAS warrant future study for potential immune therapy.NEW & NOTEWORTHY The single-cell platform mass cytometry (CyTOF) enables detection of significant changes in one million of renal cells, especially in subsets of immune cells in ischemic human kidneys distal to renal artery stenosis (RAS). We found that pro-repair cell types such as scattered tubular-progenitor-like cells, aged neutrophils, and regulatory B cells show a compensatory increase in RAS. Immune cell phenotype changes may reflect ongoing inflammation and impaired immune defense capability in the kidneys.


Assuntos
Carcinoma de Células Renais , Neoplasias Renais , Obstrução da Artéria Renal , Humanos , Idoso , Carcinoma de Células Renais/patologia , Obstrução da Artéria Renal/patologia , Artéria Renal , Rim/patologia , Isquemia/patologia , Fenótipo , Inflamação/patologia , Neoplasias Renais/patologia
16.
Cancer Sci ; 115(7): 2286-2300, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38680094

RESUMO

SNHG3, a long noncoding RNA (lncRNA), has been linked to poor outcomes in patients with liver hepatocellular carcinoma (LIHC). In this study, we found that SNHG3 was overexpressed in LIHC and associated with poor outcomes in patients with LIHC. Functional assays, including colony formation, spheroid formation, and in vivo assays showed that SNHG3 promoted stemness of cancer stem cells (CSC) and tumor growth in vivo by interacting with microRNA-502-3p (miR-502-3p). miR-502-3p inhibitor repressed the tumor-suppressing effects of SNHG3 depletion. Finally, by RNA pull-down, dual-luciferase reporter assay, m6A methylation level detection, and m6A-IP-qPCR assays, we found that miR-502-3p targeted YTHDF3 to regulate the translation of integrin alpha-6 (ITGA6) and targeted HBXIP to inhibit the m6A modification of ITGA6 through methyltransferase-like 3 (METTL3). Our study revealed that SNHG3 controls the YTHDF3/ITGA6 and HBXIP/METTL3/ITGA6 pathways by repressing miR-502-3p expression to sustain the self-renewal properties of CSC in LIHC.


Assuntos
Carcinoma Hepatocelular , Regulação Neoplásica da Expressão Gênica , Integrina alfa6 , Neoplasias Hepáticas , MicroRNAs , Células-Tronco Neoplásicas , RNA Longo não Codificante , Animais , Feminino , Humanos , Masculino , Camundongos , Pessoa de Meia-Idade , Carcinoma Hepatocelular/genética , Carcinoma Hepatocelular/patologia , Carcinoma Hepatocelular/metabolismo , Linhagem Celular Tumoral , Proliferação de Células/genética , Integrina alfa6/metabolismo , Integrina alfa6/genética , Neoplasias Hepáticas/genética , Neoplasias Hepáticas/patologia , Neoplasias Hepáticas/metabolismo , Metiltransferases/metabolismo , Metiltransferases/genética , Camundongos Nus , MicroRNAs/genética , MicroRNAs/metabolismo , Células-Tronco Neoplásicas/metabolismo , Células-Tronco Neoplásicas/patologia , RNA Longo não Codificante/genética , RNA Longo não Codificante/metabolismo
17.
Anal Chem ; 96(4): 1717-1724, 2024 01 30.
Artigo em Inglês | MEDLINE | ID: mdl-38217876

RESUMO

In this work, we demonstrate for the first time the application of the phosphorothioated-terminal hairpin formation and self-priming extension (PS-THSP) reaction for miRNA assays. A self-priming amplification accelerating CRISPR sensor was well-established for sensitive and specific miRNA detection by integrating the PS-THSP reaction and CRISPR/Cas12a system. The sensor consists of three steps: (1) the formation of a complete PS-THSP template in the presence of target miRNA and ligase; (2) the exponential isothermal amplification of the PS-THSP reaction under the action of DNA polymerase; (3) the activation of the CRISPR/Cas12a fluorescence system to generate signals. We used miR-21 as a model target. The sensor can achieve sensitive detection of miR-21 without the involvement of any primers, and the special design of the CRISPR proto-spacer neighbor motif (PAM) sequence effectively avoids the interference of the background signal. In addition, the sensor can not only identify single-base mutant homologous sequences but also show stable performance in complex biological matrices. We have successfully used this sensor to accurately analyze miR-21 in different cell lines and real clinical samples, demonstrating its great potential in clinical diagnosis.


Assuntos
Técnicas Biossensoriais , MicroRNAs , Bioensaio , Linhagem Celular , Repetições Palindrômicas Curtas Agrupadas e Regularmente Espaçadas , Primers do DNA , MicroRNAs/genética , Técnicas de Amplificação de Ácido Nucleico
18.
Biochem Biophys Res Commun ; 723: 150222, 2024 09 03.
Artigo em Inglês | MEDLINE | ID: mdl-38850813

RESUMO

Salinity has become a crucial environmental factor that restricts plant growth, development, and productivity. Nevertheless, the mechanisms by which plants react to salt stress remain inadequately comprehended. In this study, we identified maize brassinosteroid-signaling kinase gene ZmBSK7 which is homologous to AtBSK1. Our results showed that ZmBSK7 is induced by salt stress and ZmBSK7 localizes in the plasma membrane. ZmBSK7 overexpression increases salt tolerance, while its knockdown decreases salt tolerance in maize. ZmBSK7 reduces the malondialdehyde (MDA) content and the percentage of electrolyte leakage, and also elevates the activities of antioxidant enzymes. Furthermore, ZmBSK7 promotes K+ content accumulation and reduces Na+/K+ ratio. Further found that ZmBSK7 physically interacts with K+ efflux antiporter 2 (ZmKEA2) in vivo and in vitro. Salt stress also increased the expression of ZmKEA2. Thus, ZmBSK7 improves salt tolerance in maize by affecting ZmKEA2 expression to promote K+ content accumulation and reduce Na+/K+ ratio. This study enhances the comprehension of BSK proteins and establishes a theoretical foundation for investigating salt stress tolerance in plants.


Assuntos
Regulação da Expressão Gênica de Plantas , Proteínas de Plantas , Tolerância ao Sal , Zea mays , Zea mays/genética , Zea mays/metabolismo , Tolerância ao Sal/genética , Proteínas de Plantas/metabolismo , Proteínas de Plantas/genética , Estresse Salino , Transdução de Sinais , Brassinosteroides/metabolismo , Potássio/metabolismo , Proteínas Quinases/metabolismo , Proteínas Quinases/genética , Plantas Geneticamente Modificadas
19.
BMC Med ; 22(1): 435, 2024 Oct 08.
Artigo em Inglês | MEDLINE | ID: mdl-39379928

RESUMO

BACKGROUND: Health-related stigma and its internalization among individuals with chronic health conditions contribute to impaired mental and physical health and quality of life. Research on health-related stigma has been siloed, with disease-specific measures that may not capture the experiences of individuals with multiple health conditions and that prevent comparisons across health conditions. The current study aimed to develop and test a transdiagnostic measure of internalized health-related stigma for use among adults with different physical health conditions. METHODS: An existing measure of internalized mental health stigma was adapted to assess stigma due to chronic physical health conditions following COSMIN procedures, with input from advisory boards of community members living with a range of stigmatized health conditions (obesity, type 1 and type 2 diabetes, skin diseases, HIV, chronic pain, and cancers) and of health professionals who specialized in these conditions. The new Internalized Health-Related Stigma (I-HEARTS) Scale was tested in an online sample of 300 adults with these health conditions, recruited from ResearchMatch. Additional psychosocial measures of mental health and quality of life were administered, and participants provided information about their health conditions and demographic characteristics. Exploratory factor analysis and tests of reliability and validity were conducted to determine the psychometric properties of the I-HEARTS Scale, and k-means clustering and receiver of characteristic curve analysis were used to determine a clinically meaningful cutoff score indicating high levels of internalized stigma. RESULTS: Factor analysis results yielded a 25-item scale with a 3-factor solution, with subscales of Perceived and Anticipated Stigma, Stereotype Application and Self-Devaluation, and Stigma Resistance. Psychometric properties for internal consistency, inter-item and item-total correlations, and test-retest reliability were strong. Certain demographics (e.g., younger age) and characteristics related to health conditions (e.g., greater symptom severity) were associated with higher levels of internalized stigma. I-HEARTS Scale scores correlated moderately to strongly with related but distinct psychosocial measures, and a cutoff score of 3.40 or higher on the 1-7 rating scale was determined to indicate clinically meaningful levels of internalized stigma. CONCLUSIONS: The I-HEARTS Scale is a reliable and valid measure for the assessment of internalized health-related stigma among adults with varied stigmatized chronic health conditions. STUDY PRE-REGISTRATION: https://osf.io/84c5d/?view_only=87238512f6d6475c87f8f64280a8a15f .


Assuntos
Estigma Social , Humanos , Masculino , Feminino , Adulto , Pessoa de Meia-Idade , Qualidade de Vida/psicologia , Idoso , Psicometria/métodos , Inquéritos e Questionários , Doença Crônica/psicologia , Adulto Jovem , Reprodutibilidade dos Testes
20.
Small ; 20(22): e2308371, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38150631

RESUMO

By increasing the content of Ni3+, the catalytic activity of nickel-based catalysts for the oxygen evolution reaction (OER), which is still problematic with current synthesis routes, can be increased. Herein, a Ni3+-rich of Ni3S4/FeS on FeNi Foam (Ni3S4/FeS@FNF) via anodic electrodeposition to direct obtain high valence metal ions for OER catalyst is presented. XPS showed that the introduction of Fe not only further increased the Ni3+ concentration in Ni3S4/FeS to 95.02%, but also inhibited the dissolution of NiOOH by up to seven times. Furthermore, the OER kinetics is enhanced by the combination of the inner Ni3S4/FeS heterostructures and the electrochemically induced surface layers of oxides/hydroxides. Ni3S4/FeS@FNF shows the most excellent OER activity with a low Tafel slope of 11.2 mV dec-1 and overpotentials of 196 and 445 mV at current densities of 10 and 1400 mA cm-2, respectively. Furthermore, the Ni3S4/FeS@FNF catalyst can be operated stably at 1500 mA cm-2 for 200 h without significant performance degradation. In conclusion, this work has significantly increased the high activity Ni3+ content in nickel-based OER electrocatalysts through an anodic electrodeposition strategy. The preparation process is time-saving and mature, which is expected to be applied in large-scale industrialization.

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