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Exposure of mitochondrial DNA (mtDNA) to the cytosol activates innate immune responses. But the mechanisms by which mtDNA crosses the inner mitochondrial membrane are unknown. Here, we found that the inner mitochondrial membrane protein prohibitin 1 (PHB1) plays a critical role in mtDNA release by regulating permeability across the mitochondrial inner membrane. Loss of PHB1 results in alterations in mitochondrial integrity and function. PHB1-deficient macrophages, serum from myeloid-specific PHB1 KO (Phb1MyeKO) mice, and peripheral blood mononuclear cells from neonatal sepsis patients show increased interleukin-1ß (IL-1ß) levels. PHB1 KO mice are also intolerant of lipopolysaccharide shock. Phb1-depleted macrophages show increased cytoplasmic release of mtDNA and inflammatory responses. This process is suppressed by cyclosporine A and VBIT-4, which inhibit the mitochondrial permeability transition pore (mPTP) and VDAC oligomerization. Inflammatory stresses downregulate PHB1 expression levels in macrophages. Under normal physiological conditions, the inner mitochondrial membrane proteins, AFG3L2 and SPG7, are tethered to PHB1 to inhibit mPTP opening. Downregulation of PHB1 results in enhanced interaction between AFG3L2 and SPG7, mPTP opening, mtDNA release, and downstream inflammatory responses.
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DNA Mitocondrial , Proibitinas , Animais , Humanos , Camundongos , ATPases Associadas a Diversas Atividades Celulares/metabolismo , DNA Mitocondrial/genética , Leucócitos Mononucleares/metabolismo , Metaloendopeptidases/metabolismo , Proibitinas/metabolismo , Proteínas Repressoras/metabolismo , Poro de Transição de Permeabilidade MitocondrialRESUMO
CCT2 serves as an aggrephagy receptor that plays a crucial role in the clearance of solid aggregates, yet the underlying molecular mechanisms by which CCT2 regulates solid aggrephagy are not fully understood. Here we report that the binding of Cct2 to Atg8 is governed by two distinct regulatory mechanisms: Atg1-mediated Cct2 phosphorylation and the interaction between Cct2 and Atg11. Atg1 phosphorylates Cct2 at Ser412 and Ser470, and disruption of these phosphorylation sites impairs solid aggrephagy by hindering Cct2-Atg8 binding. Additionally, we observe that Atg11, an adaptor protein involved in selective autophagy, directly associates with Cct2 through its CC4 domain. Deficiency in this interaction significantly weakens the association of Cct2 with Atg8. The requirement of Atg1-mediated Cct2 phosphorylation and of Atg11 for CCT2-LC3C binding and subsequent aggrephagy is conserved in mammalian cells. These findings provide insights into the crucial roles of Atg1-mediated Cct2 phosphorylation and Atg11-Cct2 binding as key mediators governing the interaction between Cct2 and Atg8 during the process of solid aggrephagy.
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During autophagosome formation in mammalian cells, isolation membranes (IMs; autophagosome precursors) dynamically contact the ER. Here, we demonstrated that the ER-localized metazoan-specific autophagy protein EPG-3/VMP1 controls ER-IM contacts. Loss of VMP1 causes stable association of IMs with the ER, thus blocking autophagosome formation. Interaction of WIPI2 with the ULK1/FIP200 complex and PI(3)P contributes to the formation of ER-IM contacts, and these interactions are enhanced by VMP1 depletion. VMP1 controls contact formation by promoting SERCA (sarco[endo]plasmic reticulum calcium ATPase) activity. VMP1 interacts with SERCA and prevents formation of the SERCA/PLN/SLN inhibitory complex. VMP1 also modulates ER contacts with lipid droplets, mitochondria, and endosomes. These ER contacts are greatly elevated by the SERCA inhibitor thapsigargin. Calmodulin acts as a sensor/effector to modulate the ER contacts mediated by VMP1/SERCA. Our study provides mechanistic insights into the establishment and disassociation of ER-IM contacts and reveals that VMP1 modulates SERCA activity to control ER contacts.
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Autofagossomos/enzimologia , Retículo Endoplasmático/enzimologia , Membranas Intracelulares/enzimologia , Proteínas de Membrana/metabolismo , ATPases Transportadoras de Cálcio do Retículo Sarcoplasmático/metabolismo , Animais , Animais Geneticamente Modificados , Proteína Homóloga à Proteína-1 Relacionada à Autofagia/genética , Proteína Homóloga à Proteína-1 Relacionada à Autofagia/metabolismo , Proteínas Relacionadas à Autofagia , Células COS , Sistemas CRISPR-Cas , Caenorhabditis elegans/enzimologia , Caenorhabditis elegans/genética , Proteínas de Caenorhabditis elegans/genética , Proteínas de Caenorhabditis elegans/metabolismo , Proteínas de Ligação ao Cálcio/metabolismo , Chlorocebus aethiops , Genótipo , Células HEK293 , Células HeLa , Humanos , Peptídeos e Proteínas de Sinalização Intracelular/genética , Peptídeos e Proteínas de Sinalização Intracelular/metabolismo , Gotículas Lipídicas/metabolismo , Proteínas de Membrana/genética , Proteínas Musculares/metabolismo , Fenótipo , Fosfatos de Fosfatidilinositol/metabolismo , Proteolipídeos/metabolismo , Interferência de RNA , ATPases Transportadoras de Cálcio do Retículo Sarcoplasmático/genética , TransfecçãoRESUMO
ATP9A, a lipid flippase of the class II P4-ATPases, is involved in cellular vesicle trafficking. Its homozygous variants are linked to neurodevelopmental disorders in humans. However, its physiological function, the underlying mechanism as well as its pathophysiological relevance in humans and animals are still largely unknown. Here, we report two independent families in which the nonsense mutations c.433C>T/c.658C>T/c.983G>A (p. Arg145*/p. Arg220*/p. Trp328*) in ATP9A (NM_006045.3) cause autosomal recessive hypotonia, intellectual disability (ID) and attention deficit hyperactivity disorder (ADHD). Atp9a null mice show decreased muscle strength, memory deficits and hyperkinetic movement disorder, recapitulating the symptoms observed in patients. Abnormal neurite morphology and impaired synaptic transmission are found in the primary motor cortex and hippocampus of the Atp9a null mice. ATP9A is also required for maintaining neuronal neurite morphology and the viability of neural cells in vitro. It mainly localizes to endosomes and plays a pivotal role in endosomal recycling pathway by modulating small GTPase RAB5 and RAB11 activation. However, ATP9A pathogenic mutants have aberrant subcellular localization and cause abnormal endosomal recycling. These findings provide strong evidence that ATP9A deficiency leads to neurodevelopmental disorders and synaptic dysfunctions in both humans and mice, and establishes novel regulatory roles for ATP9A in RAB5 and RAB11 activity-dependent endosomal recycling pathway and neurological diseases.
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Transtorno do Deficit de Atenção com Hiperatividade , Animais , Humanos , Camundongos , Transtorno do Deficit de Atenção com Hiperatividade/metabolismo , Endossomos/metabolismo , Transporte Proteico , Proteínas rab5 de Ligação ao GTP/genética , Proteínas rab5 de Ligação ao GTP/metabolismoRESUMO
BACKGROUND: US Hispanics/Latinos are disproportionately susceptible to metabolic syndrome (MetS), attributed in part to systemic inequities related to health and lifestyle factors such as low physical activity (PA) levels, diet quality, alcohol use, tobacco use, and sleep disorder. Gender and heritage group differences are vastly understudied and need to be examined in this heterogeneous population. PURPOSE: To examine the relationships between select health and lifestyle factors and MetS among Hispanic gender and heritage subgroups (Hypothesis 1) and determine whether gender and heritage moderate those relationships (Hypothesis 2). METHODS: Participants included 14,155 Hispanic Americans aged 18-76 (59% female, mean age 45.92 ± 13.97) from seven heritage subgroups. This secondary analysis of cross-sectional data from the observational Hispanic Community Health Study/Study of Latinos (HCHS/SOL) dataset used hierarchical multinomial logistic regression to test Hypothesis 1; the dependent variable, MetS, included three categories delineating absence of MetS and presence of MetS with or without related medication use. Hayes' PROCESS macro tested Hypothesis 2. RESULTS: Low PA and sleep-disordered breathing (SDB) each had significant (pâ <â .001) predictive value of MetS group membership, whereas both low and high alcohol use (pâ <â .001) were associated with decreased MetS risk. Cigarette pack-years were not significantly associated with MetS outcomes. Gender moderated the association between MetS and alcohol use (pâ <â .001), cigarette pack-years (pâ <â .001), and SDB (pâ <â .001) such that the effects on MetS were higher in females than males. The association between MetS and diet quality (pâ <â .001) was stronger among males than in females. CONCLUSIONS: Gender and heritage differences were prominent among study variables.
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Síndrome Metabólica , Síndromes da Apneia do Sono , Adulto , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Transversais , Hispânico ou Latino , Estilo de Vida , Síndrome Metabólica/epidemiologia , Prevalência , Saúde Pública , Fatores de Risco , Síndromes da Apneia do Sono/epidemiologia , Adolescente , Adulto Jovem , IdosoRESUMO
Switching of vascular smooth muscle cells (VSMCs) from a contractile phenotype to a dedifferentiated (proliferative) phenotype contributes to neointima formation, which has been demonstrated to possess a tumor-like nature. Dysregulated glucose and lipid metabolism is recognized as a hallmark of tumors but has not thoroughly been elucidated in neointima formation. Here, we investigated the cooperative role of glycolysis and fatty acid synthesis in vascular injury-induced VSMC dedifferentiation and neointima formation. We found that the expression of hypoxia-inducible factor-1α (HIF-1α) and its target 6-phosphofructo-2-kinase/fructose-2,6-bisphosphatase (PFKFB3), a critical glycolytic enzyme, were induced in the neointimal VSMCs of human stenotic carotid arteries and wire-injured mouse carotid arteries. HIF-1α overexpression led to elevated glycolysis and resulted in a decreased contractile phenotype while promoting VSMC proliferation and activation of the mechanistic target of rapamycin complex 1 (mTORC1). Conversely, silencing Pfkfb3 had the opposite effects. Mechanistic studies demonstrated that glycolysis generates acetyl coenzyme A to fuel de novo fatty acid synthesis and mTORC1 activation. Whole-transcriptome sequencing analysis confirmed the increased expression of PFKFB3 and fatty acid synthetase (FASN) in dedifferentiated VSMCs. More importantly, FASN upregulation was observed in neointimal VSMCs of human stenotic carotid arteries. Finally, interfering with PFKFB3 or FASN suppressed vascular injury-induced mTORC1 activation, VSMC dedifferentiation, and neointima formation. Together, this study demonstrated that PFKFB3-mediated glycolytic reprogramming and FASN-mediated lipid metabolic reprogramming are distinctive features of VSMC phenotypic switching and could be potential therapeutic targets for treating vascular diseases with neointima formation. © 2023 The Pathological Society of Great Britain and Ireland.
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Músculo Liso Vascular , Lesões do Sistema Vascular , Camundongos , Humanos , Animais , Hiperplasia/patologia , Músculo Liso Vascular/patologia , Proliferação de Células , Neointima/patologia , Movimento Celular , Células Cultivadas , Modelos Animais de Doenças , Fenótipo , Ácidos Graxos/metabolismo , Alvo Mecanístico do Complexo 1 de Rapamicina/genética , Alvo Mecanístico do Complexo 1 de Rapamicina/metabolismo , Alvo Mecanístico do Complexo 1 de Rapamicina/farmacologia , Miócitos de Músculo Liso/patologiaRESUMO
Mutations in the human autophagy gene EPG5 cause the multisystem disorder Vici syndrome. Here we demonstrated that EPG5 is a Rab7 effector that determines the fusion specificity of autophagosomes with late endosomes/lysosomes. EPG5 is recruited to late endosomes/lysosomes by direct interaction with Rab7 and the late endosomal/lysosomal R-SNARE VAMP7/8. EPG5 also binds to LC3/LGG-1 (mammalian and C. elegans Atg8 homolog, respectively) and to assembled STX17-SNAP29 Qabc SNARE complexes on autophagosomes. EPG5 stabilizes and facilitates the assembly of STX17-SNAP29-VAMP7/8 trans-SNARE complexes, and promotes STX17-SNAP29-VAMP7-mediated fusion of reconstituted proteoliposomes. Loss of EPG5 activity causes abnormal fusion of autophagosomes with various endocytic vesicles, in part due to elevated assembly of STX17-SNAP25-VAMP8 complexes. SNAP25 knockdown partially suppresses the autophagy defect caused by EPG5 depletion. Our study reveals that EPG5 is a Rab7 effector involved in autophagosome maturation, providing insight into the molecular mechanism underlying Vici syndrome.
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Agenesia do Corpo Caloso/genética , Autofagossomos/metabolismo , Catarata/genética , Endossomos/metabolismo , Lisossomos/metabolismo , Proteínas/genética , Proteínas rab de Ligação ao GTP/genética , Agenesia do Corpo Caloso/metabolismo , Agenesia do Corpo Caloso/patologia , Sequência de Aminoácidos , Animais , Autofagossomos/ultraestrutura , Autofagia/genética , Proteínas Relacionadas à Autofagia , Caenorhabditis elegans/genética , Caenorhabditis elegans/metabolismo , Proteínas de Caenorhabditis elegans/genética , Proteínas de Caenorhabditis elegans/metabolismo , Catarata/metabolismo , Catarata/patologia , Endossomos/ultraestrutura , Regulação da Expressão Gênica , Células HeLa , Humanos , Proteínas de Membrana Lisossomal , Lisossomos/ultraestrutura , Fusão de Membrana , Proteínas Associadas aos Microtúbulos/genética , Proteínas Associadas aos Microtúbulos/metabolismo , Ligação Proteica , Proteínas/metabolismo , Proteínas Qa-SNARE/genética , Proteínas Qa-SNARE/metabolismo , Proteínas Qb-SNARE/genética , Proteínas Qb-SNARE/metabolismo , Proteínas Qc-SNARE/genética , Proteínas Qc-SNARE/metabolismo , Proteínas R-SNARE/genética , Proteínas R-SNARE/metabolismo , Alinhamento de Sequência , Homologia de Sequência de Aminoácidos , Transdução de Sinais , Proteína 25 Associada a Sinaptossoma/genética , Proteína 25 Associada a Sinaptossoma/metabolismo , Proteínas de Transporte Vesicular , Proteínas rab de Ligação ao GTP/metabolismo , proteínas de unión al GTP Rab7RESUMO
Maintaining mitochondrial homeostasis is a potential therapeutic strategy for various diseases, including neurodegenerative diseases, cardiovascular diseases, metabolic disorders, and cancer. Selective degradation of mitochondria by autophagy (mitophagy) is a fundamental mitochondrial quality control mechanism conserved from yeast to humans. Indeed, small-molecule modulators of mitophagy are valuable pharmaceutical tools that can be used to dissect complex biological processes and turn them into potential drugs. In the past few years, pharmacological regulation of mitophagy has shown promising therapeutic efficacy in various disease models. However, with the increasing number of chemical mitophagy modulator studies, frequent methodological flaws can be observed, leading some studies to draw unreliable or misleading conclusions. This review attempts (a) to summarize the molecular mechanisms of mitophagy; (b) to propose a Mitophagy Modulator Characterization System (MMCS); (c) to perform a comprehensive analysis of methods used to characterize mitophagy modulators, covering publications over the past 20 years; (d) to provide novel targets for pharmacological intervention of mitophagy. We believe this review will provide a panorama of current research on chemical mitophagy modulators and promote the development of safe and robust mitophagy modulators with therapeutic potential by introducing high methodological standards.
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Doenças Cardiovasculares , Neoplasias , Humanos , Mitofagia , Autofagia , Mitocôndrias/metabolismo , Doenças Cardiovasculares/tratamento farmacológico , Doenças Cardiovasculares/metabolismo , Neoplasias/tratamento farmacológico , Neoplasias/metabolismoRESUMO
BACKGROUND AND AIMS: Preoperative prediction of microvascular invasion (MVI) using a noninvasive method remain unresolved, especially in HBV-related in intrahepatic cholangiocarcinoma (ICC). This study aimed to build and validate a preoperative prediction model for MVI in HBV-related ICC. METHODS: Patients with HBV-associated ICC undergoing curative surgical resection were identified. Univariate and multivariate logistic regression analyses were performed to determine the independent risk factors of MVI in the training cohort. Then, a prediction model was built by enrolling the independent risk factors. The predictive performance was validated by receiver operator characteristic curve (ROC) and calibration in the validation cohort. RESULTS: Consecutive 626 patients were identified and randomly divided into the training (418, 67%) and validation (208, 33%) cohorts. Multivariate analysis showed that TBIL, CA19-9, tumor size, tumor number, and preoperative image lymph node metastasis were independently associated with MVI. Then, a model was built by enrolling former fiver risk factors. In the validation cohort, the performance of this model showed good calibration. The area under the curve was 0.874 (95% CI: 0.765-0.894) and 0.729 (95%CI: 0.706-0.751) in the training and validation cohort, respectively. Decision curve analysis showed an obvious net benefit from the model. CONCLUSION: Based on clinical data, an easy model was built for the preoperative prediction of MVI, which can assist clinicians in surgical decision-making and adjuvant therapy.
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Neoplasias dos Ductos Biliares , Colangiocarcinoma , Humanos , Vírus da Hepatite B , Colangiocarcinoma/cirurgia , Antígeno CA-19-9 , Neoplasias dos Ductos Biliares/cirurgia , Ductos Biliares Intra-HepáticosRESUMO
Myeloid-derived suppressor cells (MDSCs) are a heterogeneous population of immature myeloid cells which are immunosuppressive and glycolytically inactive in inflammatory diseases. However, it is unknown whether MDSCs contribute to ischemic stroke and how glycolysis regulates MDSC function in such a context. Here, we showed that MDSCs arise in the blood of patients at early phase of stroke. Similar results were observed in temporary middle cerebral artery occlusion-induced cerebral ischemic mice. Pharmaceutical exhaustion of MDSCs aggravated, while adoptive transfer of MDSCs rescued the ischemic brain injury. However, the differentiation of MDSCs into immunopotent myeloid cells which coincides with increased glycolysis was observed in the context of ischemic stroke. Mechanistically, the glycolytic product lactate autonomously induces MDSC differentiation through activation of mTORC1, and paracrinely activates Th1 and Th17 cells. Moreover, gene knockout or inhibition of the glycolytic enzyme PFKFB3 increased endogenous MDSCs by blocking their differentiation, and improved ischemic brain injury. Collectively, these results revealed that glycolytic switch decreases the immunosuppressive and neuroprotective role of MDSCs in ischemic stroke and pharmacological targeting MDSCs via glycolysis inhibition constitutes a promising therapeutic strategy for ischemic stroke.
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Lesões Encefálicas , AVC Isquêmico , Células Supressoras Mieloides , Animais , Glicólise , Humanos , Imunossupressores , Camundongos , Camundongos Endogâmicos C57BLRESUMO
Mitochondrial autophagy, or mitophagy, is a major mechanism involved in mitochondrial quality control via selectively removing damaged or unwanted mitochondria. Interactions between LC3 and mitophagy receptors such as FUNDC1, which harbors an LC3-interacting region (LIR), are essential for this selective process. However, how mitochondrial stresses are sensed to activate receptor-mediated mitophagy remains poorly defined. Here, we identify that the mitochondrially localized PGAM5 phosphatase interacts with and dephosphorylates FUNDC1 at serine 13 (Ser-13) upon hypoxia or carbonylcyanide p-trifluoromethoxyphenylhydrazone (FCCP) treatment. Dephosphorylation of FUNDC1 catalyzed by PGAM5 enhances its interaction with LC3, which is abrogated following knockdown of PGAM5 or the introduction of a cell-permeable unphosphorylated peptide encompassing the Ser-13 and LIR of FUNDC1. We further observed that CK2 phosphorylates FUNDC1 to reverse the effect of PGAM5 in mitophagy activation. Our results reveal a mechanistic signaling pathway linking mitochondria-damaging signals to the dephosphorylation of FUNDC1 by PGAM5, which ultimately induces mitophagy.
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Proteínas de Transporte/metabolismo , Caseína Quinase II/metabolismo , Proteínas de Membrana/metabolismo , Proteínas Mitocondriais/metabolismo , Mitofagia , Processamento de Proteína Pós-Traducional , Sequência de Aminoácidos , Sequência Consenso , Retroalimentação Fisiológica , Células HeLa , Humanos , Proteínas de Membrana/química , Proteínas Associadas aos Microtúbulos/metabolismo , Proteínas Mitocondriais/química , Dados de Sequência Molecular , Fosfoproteínas Fosfatases , FosforilaçãoRESUMO
Báa nnilah is a chronic illness self-management program designed by and for the Apsáalooke (Crow) community. Arising from a collaboration between an Indigenous nonprofit organization and a university-based research team, Báa nnilah's development, implementation, and evaluation have been influenced by both Indigenous and Western research paradigms (WRPs). Báa nnilah was evaluated using a randomized wait-list control group design. In a WRP, contamination, or intervention information shared by the intervention group with the control group, is actively discouraged as it makes ascertaining causality difficult, if not impossible. This approach is not consonant with Apsáalooke cultural values that include the encouragement of sharing helpful information with others, supporting an Indigenous research paradigm's (IRP) goal of benefiting the community. The purpose of this paper is to address contamination and sharing as an area of tension between WRP and IRP. We describe how the concepts of contamination and sharing within Báa nnilah's implementation and evaluation are interpreted differently when viewed from these contrasting paradigms, and set forth a call for greater exploration of Indigenous research approaches for developing, implementing, and evaluating intervention programs in Indigenous communities. (Improving Chronic Illness Management with the Apsáalooke Nation: The Báa nnilah Project.: NCT03036189), ClinicalTrials. gov: NCT03036189).
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Serviços de Saúde do Indígena , Grupos Populacionais , Doença Crônica , Humanos , UniversidadesRESUMO
BACKGROUND: Gestational diabetes mellitus (GDM) is a growing public health concern and maternal obesity and poor dietary intakes could be implicated. Dietary polyphenols and fiber mitigate the risk of diabetes and its complications, but little is known about their efficacy in preventing GDM. OBJECTIVES: We examined the effects of whole blueberry and soluble fiber supplementation on primary outcomes of cardiometabolic profiles in women at high risk of developing GDM. METHODS: Women (n = 34; mean ± SD age: 27 ± 5 y; BMI: 35.5 ± 4.0 kg/m2; previous history of GDM â¼56%; Hispanic â¼79%) were recruited in early pregnancy (<20 weeks of gestation) and randomly assigned to 1 of the following 2 groups for 18 wk: intervention (280 g whole blueberries and 12 g soluble fiber per day) and standard prenatal care (control). Both groups received nutrition education and maintained 24-h food recalls throughout the study. Data on anthropometrics, blood pressure, and blood samples for biochemical analyses were collected at baseline (<20 weeks), midpoint (24-28 weeks), and end (32-36 weeks) of gestation. Diagnosis of GDM was based on a 2-step glucose challenge test (GCT). Data were analyzed using a mixed-model ANOVA. RESULTS: Maternal weight gain was significantly lower in the dietary intervention than in the control group at the end of the trial (mean ± SD: 6.8 ± 3.2 kg compared with 12.0 ± 4.1 kg, P = 0.001). C-reactive protein was also lower in the intervention than in the control group (baseline: 6.1 ± 4.0 compared with 6.8 ± 7.2 mg/L; midpoint: 6.1 ± 3.7 compared with 7.5 ± 7.3 mg/L; end: 5.5 ± 2.2 compared with 9.5 ± 6.6 mg/L, respectively, P = 0.002). Blood glucose based on GCT was lower in the intervention than in the control (100 ± 33 mg/dL compared with 131 ± 40 mg/dL, P < 0.05). Conventional lipids (total, LDL, and HDL cholesterol and triglycerides) did not differ between groups over time. No differences were noted in infant birth weight. CONCLUSIONS: Whole blueberry and soluble fiber supplementation may prevent excess gestational weight gain and improve glycemic control and inflammation in women with obesity.This trial was registered at clinicaltrials.gov as NCT03467503.
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Mirtilos Azuis (Planta) , Diabetes Gestacional/prevenção & controle , Dieta , Fibras na Dieta/administração & dosagem , Obesidade Materna/dietoterapia , Fenômenos Fisiológicos da Nutrição Pré-Natal , Adulto , Biomarcadores/sangue , Glicemia , Feminino , Hemoglobinas Glicadas/metabolismo , Humanos , Inflamação/sangue , Inflamação/metabolismo , Insulina , Lipídeos/sangue , Obesidade Materna/complicações , Gravidez , Adulto JovemRESUMO
Caffeine induces multiple vascular effects. In this study we investigated the angiogenic effect of physiological concentrations of caffeine with focus on endothelial cell behaviors (migration and proliferation) during angiogenesis and its mitochondrial and bioenergetic mechanisms. We showed that caffeine (10-50 µM) significantly enhanced angiogenesis in vitro, evidenced by concentration-dependent increases in tube formation, and migration of human umbilical vein endothelial cells (HUVECs) without affecting cell proliferation. Caffeine (50 µM) enhanced endothelial migration via activation of cAMP/PKA/AMPK signaling pathway, which was mimicked by cAMP analog 8-Br-cAMP, and blocked by PKA inhibitor H89, adenylate cyclase inhibitor SQ22536 or AMPK inhibitor compound C. Furthermore, caffeine (50 µM) induced significant mitochondrial shortening through the increased phosphorylation of mitochondrial fission protein dynamin-related protein 1 (Drp1) in HUVECs, which increased its activity to regulate mitochondrial fission. Pharmacological blockade of Drp1 by Mdivi-1 (10 µM) or disturbance of mitochondrial fission by Drp1 silencing markedly suppressed caffeine-induced lamellipodia formation and endothelial cell migration. Moreover, we showed that caffeine-induced mitochondrial fission led to accumulation of more mitochondria in lamellipodia regions and augmentation of mitochondrial energetics, both of which were necessary for cell migration. In a mouse model of hindlimb ischemia, administration of caffeine (0.05% in 200 mL drinking water daily, for 14 days) significantly promoted angiogenesis and perfusion as well as activation of endothelial AMPK signaling in the ischemic hindlimb. Taken together, caffeine induces mitochondrial fission through cAMP/PKA/AMPK signaling pathway. Mitochondrial fission is an integral process in caffeine-induced endothelial cell migration by altering mitochondrial distribution and energetics.
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Cafeína/uso terapêutico , Endotélio/efeitos dos fármacos , Isquemia/tratamento farmacológico , Mitocôndrias/efeitos dos fármacos , Dinâmica Mitocondrial/efeitos dos fármacos , Neovascularização Fisiológica/efeitos dos fármacos , Animais , Movimento Celular/efeitos dos fármacos , Membro Posterior/efeitos dos fármacos , Células Endoteliais da Veia Umbilical Humana , Humanos , Masculino , Camundongos Endogâmicos C57BL , Pseudópodes/efeitos dos fármacos , Transdução de Sinais/efeitos dos fármacosRESUMO
In hypoxic cells, dysfunctional mitochondria are selectively removed by a specialized autophagic process called mitophagy. The ER-mitochondrial contact site (MAM) is essential for fission of mitochondria prior to engulfment, and the outer mitochondrial membrane protein FUNDC1 interacts with LC3 to recruit autophagosomes, but the mechanisms integrating these processes are poorly understood. Here, we describe a new pathway mediating mitochondrial fission and subsequent mitophagy under hypoxic conditions. FUNDC1 accumulates at the MAM by associating with the ER membrane protein calnexin. As mitophagy proceeds, FUNDC1/calnexin association attenuates and the exposed cytosolic loop of FUNDC1 interacts with DRP1 instead. DRP1 is thereby recruited to the MAM, and mitochondrial fission then occurs. Knockdown of FUNDC1, DRP1, or calnexin prevents fission and mitophagy under hypoxic conditions. Thus, FUNDC1 integrates mitochondrial fission and mitophagy at the interface of the MAM by working in concert with DRP1 and calnexin under hypoxic conditions in mammalian cells.
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Calnexina/metabolismo , Retículo Endoplasmático/metabolismo , GTP Fosfo-Hidrolases/metabolismo , Hipóxia , Proteínas de Membrana/metabolismo , Proteínas Associadas aos Microtúbulos/metabolismo , Dinâmica Mitocondrial , Proteínas Mitocondriais/metabolismo , Células Cultivadas , Dinaminas , Humanos , Mitofagia , Ligação ProteicaRESUMO
PURPOSE: The National Institutes of Health established the Patient-Reported Outcomes Measurement Information System (PROMIS) to assess health across various chronic illnesses. The standardized PROMIS measures have been used to assess symptoms in studies that included Native American participants, although the psychometric properties of these measures have not been assessed among a solely Native American population. This study aimed to assess the reliability, construct validity, and measurement invariance of a widely used PROMIS Physical Function survey among Native Americans residing on or near the Apsáalooke (Crow) Reservation who were living with chronic illnesses. METHODS: Participants aged 24 to 82 years and living with at least one chronic illness were recruited for a community-based participatory research project. Baseline data were used for the current study (N = 210). The 8-item PROMIS Physical Function 8b-Adult Short Form v2.0 was used to assess the function of upper and lower extremities, central core regions, and the ability to complete daily activities on a 5-point Likert scale. RESULTS: Results indicated that the above PROMIS survey had high internal consistency (Cronbach's α = 0.95) and split-half (r = 0.92, p < 0.001) reliabilities. Confirmatory factor analyses supported construct validity among females of the above population and when the two sex groups were combined. Results also indicated that corresponding thresholds and factor loadings were invariant across male and female groups. CONCLUSIONS: The above PROMIS measure had good psychometric properties in females and when the two sex groups were combined among Native American adults living on or near the Apsáalooke reservation with chronic illnesses. Thresholds and factor loadings appeared to be invariant by sex. Future studies with a larger sample size among males and more studies on the psychometric properties of other PROMIS measures among Native American populations are needed.
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Desempenho Físico Funcional , Psicometria/métodos , Qualidade de Vida/psicologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Reprodutibilidade dos Testes , Inquéritos e Questionários , Adulto JovemRESUMO
BACKGROUND: Ovarian cancer (OC) is the second most frequent gynecological cancer and is associated with a poor prognosis because OC progression is often asymptoma-tic and is detected at a late stage. There remains an urgent need for novel targeted therapies to improve clinical outcomes in ovarian cancer. As a nitric oxide prodrug, JS-K is reported highly cytotoxic to human cancer cells such as acute myeloid leukemia, multiple myeloma and breast cancer. This study is aim to investigate the influence of JS-K on proliferation and apoptosis in ovarian cancer cells and explored possible autophagy-related mechanisms, which will contribute to future ovarian cancer therapy and supply theory support that JS-K holds great promise as a novel therapeutic agent against ovarian cancer. METHODS: The cytotoxicity, extracellular ROS/RNS activity and apoptotic effect of JS-K and indicated inhibitors on ovarian cancer cells in vitro were evaluated by MTT assay, extracellular ROS/RNS assay, caspases activities assay and western blot. Further autophagy effect of JS-K and indicated inhibitors were examined by MTT assay, cell transfection, immunofluorescence analysis, transmission electron microscopy (TEM) analysis and western blot on ovarian cancer cells in vitro. In vivo, the BALB/c-nude female mice with SKOV3 ovarian cancer cells xenograft were used to examine the efficacy of JS-K treatment on tumor growth. PCNA and p62 proteins were analyzed by immunohistochemistry. RESULTS: In vitro, JS-K inhibited the proliferation of ovarian cancer cells, induced apoptosis and cell nucleus shrinkage, enhanced the enzymatic activity of caspase-3/7/8/9, and significantly increased the production of ROS/RNS in ovarian cancer A2780 and SKOV3 cells, these effects were attenuated by inhibition of NAC. In addition, JS-K induced autophagy-related proteins and autophagosomes changes in ovarian cancer A2780 and SKOV3 cells. In vivo, JS-K inhibited tumor growth, decreased p62 protein expression and increased the expression levels of PCNA in xenograft models which were established using SKOV3 ovarian cancer cells. CONCLUSION: Taken together, we demonstrated that ROS/RNS stress-mediated apoptosis and autophagy are mechanisms by which SKOV3 cells undergo cell death after treatment with JS-K in vitro. Moreover, JS-K inhibited SKOV3 tumor growth in vivo. An alternative therapeutic approach for triggering cell death in cancer cells could constitute a useful multimodal therapies for treating ovarian cancer, which is known for its resistance to apoptosis-inducing drugs.
Assuntos
Autofagia/efeitos dos fármacos , Compostos Azo/farmacologia , Doadores de Óxido Nítrico/farmacologia , Neoplasias Ovarianas/tratamento farmacológico , Piperazinas/farmacologia , Animais , Caspases/metabolismo , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Feminino , Xenoenxertos , Humanos , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Nus , Transplante de Neoplasias , Neoplasias Ovarianas/enzimologia , Neoplasias Ovarianas/metabolismo , Neoplasias Ovarianas/patologia , Espécies Reativas de Oxigênio , Ensaios Antitumorais Modelo de XenoenxertoRESUMO
BACKGROUND: Hospital-acquired functional decline due to decreased mobility has negative impacts on patient outcomes. Current nurse-directed mobility programs lack a standardized approach to set achievable mobility goals. PURPOSE: We aimed to describe implementation and outcomes from a nurse-directed patient mobility program. METHOD: The quality improvement mobility program on the project unit was compared to a similar control unit providing usual care. The Johns Hopkins Mobility Goal Calculator was created to guide a daily patient mobility goal based on the level of mobility impairment. FINDINGS: On the project unit, patient mobility increased from 5.2 to 5.8 on the Johns Hopkins Highest Level of Mobility score, mobility goal attainment went from 54.2% to 64.2%, and patients exceeding the goal went from 23.3% to 33.5%. All results were significantly higher than the control unit. DISCUSSION: An individualized, nurse-directed, patient mobility program using daily mobility goals is a successful strategy to improve daily patient mobility in the hospital.
Assuntos
Nível de Saúde , Movimentação e Reposicionamento de Pacientes/métodos , Melhoria de Qualidade/estatística & dados numéricos , Baltimore , Humanos , Movimentação e Reposicionamento de Pacientes/classificação , Movimentação e Reposicionamento de Pacientes/estatística & dados numéricos , Planejamento de Assistência ao Paciente/normas , Planejamento de Assistência ao Paciente/estatística & dados numéricosRESUMO
Autophagy eliminates dysfunctional mitochondria in an intricate process known as mitophagy. ULK1 is critical for the induction of autophagy, but its substrate(s) and mechanism of action in mitophagy remain unclear. Here, we show that ULK1 is upregulated and translocates to fragmented mitochondria upon mitophagy induction by either hypoxia or mitochondrial uncouplers. At mitochondria, ULK1 interacts with FUNDC1, phosphorylating it at serine 17, which enhances FUNDC1 binding to LC3. A ULK1-binding-deficient mutant of FUNDC1 prevents ULK1 translocation to mitochondria and inhibits mitophagy. Finally, kinase-active ULK1 and a phospho-mimicking mutant of FUNDC1 rescue mitophagy in ULK1-null cells. Thus, we conclude that FUNDC1 regulates ULK1 recruitment to damaged mitochondria, where FUNDC1 phosphorylation by ULK1 is crucial for mitophagy.