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1.
Platelets ; 34(1): 2222184, 2023 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-37292023

RESUMEN

Although the presence of glycogen in platelets was established in the 1960s, its importance to specific functions (i.e., activation, secretion, aggregation, and clot contraction) remains unclear. Patients with glycogen storage disease often present with increased bleeding and glycogen phosphorylase (GP) inhibitors, when used as treatments for diabetes, induce bleeding in preclinical studies suggesting some role for this form of glucose in hemostasis. In the present work, we examined how glycogen mobilization affects platelet function using GP inhibitors (CP316819 and CP91149) and a battery of ex vivo assays. Blocking GP activity increased glycogen levels in resting and thrombin-activated platelets and inhibited platelet secretion and clot contraction, with minimal effects on aggregation. Seahorse energy flux analysis and metabolite supplementation experiments suggested that glycogen is an important metabolic fuel whose role is affected by platelet activation and the availability of external glucose and other metabolic fuels. Our data shed light on the bleeding diathesis in glycogen storage disease patients and offer insights into the potential effects of hyperglycemia on platelets.


What did we know? Activated platelets transition from a low-energy-requiring, resting state to a high-energy-demanding state.Platelet glycogen is degraded upon activation.Glycogen storage disorders and glycogen phosphorylase inhibitors are associated with bleeding.What did we discover? Glycogen turnover occurs in resting platelets and its degradation is important for platelet functions.Glycogen phosphorylase inhibitors block secretion and clot contraction of which the latter can be reversed with alternative metabolic fuels.Glucose derived from glycogen may be routed through TCA/OxPhos versus aerobic glycolysis.What is the impact? Glycogen breakdown contributes to the high energy requirements of platelet function.Our work offers insights into potential energy sources in activated platelets.


Asunto(s)
Enfermedad del Almacenamiento de Glucógeno , Glucogenólisis , Trombosis , Humanos , Plaquetas/metabolismo , Glucosa/metabolismo , Glucosa/farmacología , Glucógeno/metabolismo , Glucógeno/farmacología , Trombosis/metabolismo , Enfermedad del Almacenamiento de Glucógeno/metabolismo
2.
Int J Mol Sci ; 24(6)2023 Mar 08.
Artículo en Inglés | MEDLINE | ID: mdl-36982266

RESUMEN

The CRISPR/Cas9 system is a robust, efficient, and cost-effective gene editing tool widely adopted in translational studies of ocular diseases. However, in vivo CRISPR-based editing in animal models poses challenges such as the efficient delivery of the CRISPR components in viral vectors with limited packaging capacity and a Cas9-associated immune response. Using a germline Cas9-expressing mouse model would help to overcome these limitations. Here, we evaluated the long-term effects of SpCas9 expression on retinal morphology and function using Rosa26-Cas9 knock-in mice. We observed abundant SpCas9 expression in the RPE and retina of Rosa26-Cas9 mice using the real-time polymerase chain reaction (RT-PCR), Western blotting, and immunostaining. SD-OCT imaging and histological analysis of the RPE, retinal layers, and vasculature showed no apparent structural abnormalities in adult and aged Cas9 mice. Full-field electroretinogram of adult and aged Cas9 mice showed no long-term functional changes in the retinal tissues because of constitutive Cas9 expression. The current study showed that both the retina and RPE maintain their phenotypic and functional features in Cas9 knock-in mice, establishing this as an ideal animal model for developing therapeutics for retinal diseases.


Asunto(s)
Sistemas CRISPR-Cas , Retina , Ratones , Animales , Retina/metabolismo , Edición Génica/métodos , Electrorretinografía , Vectores Genéticos
3.
Arterioscler Thromb Vasc Biol ; 40(7): 1635-1650, 2020 07.
Artículo en Inglés | MEDLINE | ID: mdl-32434410

RESUMEN

OBJECTIVE: Thrombocytopenia is associated with many viral infections suggesting virions interact with and affect platelets. Consistently, viral particles are seen inside platelets, and platelet activation markers are detected in viremic patients. In this article, we sought mechanistic insights into these virion/platelet interactions by examining how platelets endocytose, traffic, and are activated by a model virion. Approach and Results: Using fluorescently tagged HIV-1 pseudovirions, 3-dimensional structured illumination microscopy, and transgenic mouse models, we probed the interactions between platelets and virions. Mouse platelets used known endocytic machinery, that is, dynamin, VAMP (vesicle-associated membrane protein)-3, and Arf6 (ADP-ribosylation factor 6), to take up and traffic HIV-1 pseudovirions. Endocytosed HIV-1 pseudovirions trafficked through early (Rab4+) and late endosomes (Rab7+), and then to an LC3+ (microtubule-associated protein 1A/1B-light chain 3) compartment. Incubation with virions induced IRAK4 (interleukin 1 receptor-associated kinase 4), Akt (protein kinase B), and IKK (IκB kinase) activation, granule secretion, and platelet-leukocyte aggregate formation. This activation required TLRs (Toll-like receptors) and MyD88 (myeloid differentiation primary response protein 88) but was less extensive and slower than activation with thrombin. In vivo, HIV-1 pseudovirions injection led to virion uptake and platelet activation, as measured by IKK activation, platelet-leukocyte aggregate formation, and mild thrombocytopenia. All were decreased in VAMP-3-/- and, megakaryocyte/platelet-specific, Arf6-/- mice. Similar platelet activation profiles (increased platelet-leukocyte aggregates, plasma platelet factor 4, and phospho-IκBα) were detected in newly diagnosed and antiretroviral therapy-controlled HIV-1+ patients. CONCLUSIONS: Collectively, our data provide mechanistic insights into the cell biology of how platelets endocytose and process virions. We propose a mechanism by which platelets sample the circulation and respond to potential pathogens that they take up.


Asunto(s)
Plaquetas/metabolismo , Endocitosis , Infecciones por VIH/sangre , VIH-1/patogenicidad , Activación Plaquetaria , Trombocitopenia/sangre , Receptores Toll-Like/sangre , Virión , Factor 6 de Ribosilación del ADP , Factores de Ribosilacion-ADP/sangre , Factores de Ribosilacion-ADP/genética , Animales , Antirretrovirales/uso terapéutico , Plaquetas/virología , Agregación Celular , Células Cultivadas , Infecciones por VIH/diagnóstico , Infecciones por VIH/tratamiento farmacológico , Infecciones por VIH/virología , Humanos , Quinasa I-kappa B/sangre , Quinasa I-kappa B/genética , Leucocitos/metabolismo , Leucocitos/virología , Ratones Endogámicos C57BL , Ratones Noqueados , Factor 88 de Diferenciación Mieloide/sangre , Factor 88 de Diferenciación Mieloide/genética , Factor Plaquetario 4/sangre , Factor Plaquetario 4/genética , Trombocitopenia/diagnóstico , Trombocitopenia/virología , Receptores Toll-Like/deficiencia , Receptores Toll-Like/genética , Proteína 3 de Membrana Asociada a Vesículas/sangre , Proteína 3 de Membrana Asociada a Vesículas/genética
4.
Can Assoc Radiol J ; 72(3): 410-417, 2021 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-32066248

RESUMEN

PURPOSE: To evaluate the degree of gastric, enteric, colonic, and rectal filling in multidetector computed tomography (MDCT) whole gastroenterography. METHODS: In this prospective study involving 124 patients, 78 and 46 patients underwent MDCT whole gastroenterography using positive and neutral oral contrast agents, respectively. The degree of filling of the stomach, small and large bowel, was qualitatively analyzed by experienced radiologists using a 3-point scoring system. RESULTS: The majority of patients received a score of ≥2 for small intestine filling using both positive and neutral contrast agents (90.5% and 78.2%, respectively), and <9% of the patients had a score of 0. The highest score for the degree of filling in the small intestine was observed in the ileum, followed by the duodenum and jejunum. There was a significant difference in the degree of filling achieved with positive and neutral contrast agents in the duodenum (P = .013) and jejunum (P = .047). More than 74% of cases had an optimal filling of the stomach, whereas >80% of the cases had an optimal filling of the colorectal segments. Only ≤5.1% had a score of 0 for the analyzed segments of the colorectum. Positive and neutral contrast agents were associated with similar degree of filling in the stomach and colon segments without a significant difference in the extent of contrast agent filling (P > .05). CONCLUSIONS: Multidetector computed tomography whole gastroenterography was found to be a simple, safe, noninvasive, painless, and effective modality for the diagnosis of stomach and bowel complications in clinical settings.


Asunto(s)
Neoplasias del Colon/diagnóstico por imagen , Medios de Contraste , Tracto Gastrointestinal/diagnóstico por imagen , Tomografía Computarizada Multidetector/métodos , Administración Oral , Adulto , Anciano , Anciano de 80 o más Años , Colon/diagnóstico por imagen , Pólipos del Colon/diagnóstico por imagen , Medios de Contraste/administración & dosificación , Femenino , Humanos , Intestino Delgado/diagnóstico por imagen , Masculino , Manitol/administración & dosificación , Persona de Mediana Edad , Estudios Prospectivos , Dosis de Radiación , Recto/diagnóstico por imagen , Estómago/diagnóstico por imagen , Ácidos Triyodobenzoicos/administración & dosificación
5.
Neural Plast ; 2020: 6283754, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-32273890

RESUMEN

The motor and nonmotor symptoms of PD involve several brain regions. However, whether α-syn pathology originating from the SNc can directly lead to the pathological changes in distant cerebral regions and induce PD-related symptoms remains unclear. Here, AAV9-synapsin-mCherry-human SNCA (A53T) was injected into the unilateral SNc of mice. Motor function and olfactory sensitivity were evaluated. Our results showed that AAV9-synapsin-mCherry-human SNCA was continuously expressed in SNc. The animals showed mild motor and olfactory dysfunction at 7 months after viral injection. The pathology in SNc was characterized by the loss of dopaminergic neurons accompanied by ER stress. In the striatum, hα-syn expression was high, CaMKß-2 and NR2B expression decreased, and active synapses reduced. In the olfactory bulb, hα-syn expression was high, and aging cells in the mitral layer increased. The results suggested that hα-syn was transported in the striatum and OB along the nerve fibers that originated from the SNc and induced pathological changes in the distant cerebral regions, which contributed to the motor and nonmotor symptoms of PD.


Asunto(s)
Neuronas/patología , Enfermedad de Parkinson/metabolismo , Enfermedad de Parkinson/patología , Porción Compacta de la Sustancia Negra/metabolismo , Porción Compacta de la Sustancia Negra/patología , Sinapsis/patología , alfa-Sinucleína/metabolismo , Adenoviridae/fisiología , Animales , Vectores Genéticos/fisiología , Masculino , Ratones Endogámicos C57BL , Bulbo Olfatorio/metabolismo , Bulbo Olfatorio/patología , alfa-Sinucleína/administración & dosificación
6.
Toxicol Mech Methods ; 30(5): 350-357, 2020 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-32189544

RESUMEN

Rotenone is a mitochondrial complex I inhibitor, which can cause the death of dopaminergic (DA) neurons and Parkinson's disease (PD). Currently, whether metformin has a protective effect on neurotoxicity induced by rotenone is unclear. The purpose of this study was to evaluate the potential protective effect of metformin against rotenone-induced neurotoxicity. PD animal model was established by unilateral rotenone injection into the right substantia nigra (SN) of C57BL/6 mice. The behavioral tests were performed by rotarod test and cylinder test. The numbers of TH-positive neurons and Iba-1 positive microglia in the SN were investigated by immunohistochemical staining. The mRNA levels of proinflammatory cytokines (TNF-α and IL-1ß) and molecules involved in endoplasmic reticulum (ER) stress (ATF4, ATF6, XBP1, Grp78, and CHOP) in the midbrain were detected by Quantitative real-time PCR. This study showed that 50 mg/kg metformin given orally daily, beginning 3 d before rotenone injection and continuing for 4 weeks following rotenone injection, significantly ameliorated dyskinesia, increased the number of TH-positive neurons, and mitigated the activation of microglia in the SN in rotenone-induced PD mice. Furthermore, 50 mg/kg metformin markedly downregulated the expression of proinflammatory cytokines (TNF-α and IL-1ß) and ER stress-related genes (ATF4, ATF6, XBP1, Grp78, and CHOP) in rotenone-induced PD mice. Metformin has a protective effect on DA neurons against rotenone-induced neurotoxicity through inhibiting neuroinflammation and ER stress in PD mouse model.


Asunto(s)
Conducta Animal/efectos de los fármacos , Neuronas Dopaminérgicas/efectos de los fármacos , Metformina/farmacología , Enfermedad de Parkinson Secundaria/prevención & control , Sustancias Protectoras/farmacología , Rotenona/toxicidad , Animales , Modelos Animales de Enfermedad , Neuronas Dopaminérgicas/inmunología , Chaperón BiP del Retículo Endoplásmico , Estrés del Retículo Endoplásmico/efectos de los fármacos , Estrés del Retículo Endoplásmico/inmunología , Inflamación , Interleucina-1beta/metabolismo , Masculino , Metformina/administración & dosificación , Ratones , Ratones Endogámicos C57BL , Microglía/efectos de los fármacos , Microglía/inmunología , Enfermedad de Parkinson Secundaria/inducido químicamente , Enfermedad de Parkinson Secundaria/inmunología , Sustancias Protectoras/administración & dosificación , Factor de Necrosis Tumoral alfa/metabolismo
7.
FASEB J ; 32(12): 6796-6807, 2018 12.
Artículo en Inglés | MEDLINE | ID: mdl-29939786

RESUMEN

Autophagy of mitochondria (mitophagy) is essential for maintaining muscle mass and healthy skeletal muscle. Patients with heritable phosphatidic acid phosphatase lipin-1-null mutations present with severe rhabdomyolysis and muscle atrophy in glycolytic muscle fibers, which are accompanied with mitochondrial aggregates and reduced mitochondrial cytochrome c oxidase activity. However, the underlying mechanisms leading to muscle atrophy as a result of lipin-1 deficiency are still not clear. In this study, we found that lipin-1 deficiency in mice is associated with a marked accumulation of abnormal mitochondria and autophagic vacuoles in glycolytic muscle fibers. Our studies using lipin-1-deficient myoblasts suggest that lipin-1 participates in B-cell leukemia (BCL)-2 adenovirus E1B 19 kDa protein-interacting protein 3 (Bnip3)-regulated mitophagy by interacting with microtubule-associated protein 1A/1B-light chain (LC)3, which is an important step in the recruitment of mitochondria to nascent autophagosomes. The requirement of lipin-1 for Bnip3-mediated mitophagy was further verified in vivo in lipin-1-deficient green fluorescent protein-LC3 transgenic mice (lipin-1-/--GFP-LC3). Finally, we showed that lipin-1 deficiency in mice resulted in defective mitochondrial adaptation to starvation-induced metabolic stress and impaired contractile muscle force in glycolytic muscle fibers. In summary, our study suggests that deregulated mitophagy arising from lipin-1 deficiency is associated with impaired muscle function and may contribute to muscle rhabdomyolysis in humans.-Alshudukhi, A. A., Zhu, J., Huang, D., Jama, A., Smith, J. D., Wang, Q. J., Esser, K. A., Ren, H. Lipin-1 regulates Bnip3-mediated mitophagy in glycolytic muscle.

8.
Nat Methods ; 12(12): 1135-8, 2015 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-26436480

RESUMEN

It remains particularly problematic to define the structures of native macromolecular assemblies, which are often of low abundance. Here we present a strategy for isolating complexes at endogenous levels from GFP-tagged transgenic cell lines. Using cross-linking mass spectrometry, we extracted distance restraints that allowed us to model the complexes' molecular architectures.


Asunto(s)
Espectrometría de Masas/métodos , Modelos Moleculares , Complejos Multiproteicos/química , Conformación Proteica , Animales , Reactivos de Enlaces Cruzados/química , Electroforesis en Gel de Poliacrilamida , Exosomas/química , Proteínas Fluorescentes Verdes/genética , Hígado/química , Ratones Transgénicos , Complejos Multiproteicos/genética , Saccharomyces cerevisiae/química , Proteínas de Saccharomyces cerevisiae/química , Sensibilidad y Especificidad
9.
Metabolomics ; 14(10): 125, 2018 09 17.
Artículo en Inglés | MEDLINE | ID: mdl-30830442

RESUMEN

INTRODUCTION: Direct injection Fourier-transform mass spectrometry (FT-MS) allows for the high-throughput and high-resolution detection of thousands of metabolite-associated isotopologues. However, spectral artifacts can generate large numbers of spectral features (peaks) that do not correspond to known compounds. Misassignment of these artifactual features creates interpretive errors and limits our ability to discern the role of representative features within living systems. OBJECTIVES: Our goal is to develop rigorous methods that identify and handle spectral artifacts within the context of high-throughput FT-MS-based metabolomics studies. RESULTS: We observed three types of artifacts unique to FT-MS that we named high peak density (HPD) sites: fuzzy sites, ringing and partial ringing. While ringing artifacts are well-known, fuzzy sites and partial ringing have not been previously well-characterized in the literature. We developed new computational methods based on comparisons of peak density within a spectrum to identify regions of spectra with fuzzy sites. We used these methods to identify and eliminate fuzzy site artifacts in an example dataset of paired cancer and non-cancer lung tissue samples and evaluated the impact of these artifacts on classification accuracy and robustness. CONCLUSION: Our methods robustly identified consistent fuzzy site artifacts in our FT-MS metabolomics spectral data. Without artifact identification and removal, 91.4% classification accuracy was achieved on an example lung cancer dataset; however, these classifiers rely heavily on artifactual features present in fuzzy sites. Proper removal of fuzzy site artifacts produces a more robust classifier based on non-artifactual features, with slightly improved accuracy of 92.4% in our example analysis.


Asunto(s)
Carcinoma de Pulmón de Células no Pequeñas/metabolismo , Análisis de Fourier , Ensayos Analíticos de Alto Rendimiento , Neoplasias Pulmonares/metabolismo , Pulmón/metabolismo , Espectrometría de Masas , Metabolómica , Carcinoma de Pulmón de Células no Pequeñas/diagnóstico , Humanos , Neoplasias Pulmonares/diagnóstico
10.
Behav Brain Funct ; 14(1): 7, 2018 Mar 19.
Artículo en Inglés | MEDLINE | ID: mdl-29554926

RESUMEN

BACKGROUND: Following a social defeat, the balanced establishment and extinction of aversive information is a beneficial strategy for individual survival. Abnormal establishment or extinction is implicated in the development of mental disorders. This study investigated the time course of the establishment and extinction of aversive information from acute social defeat and the temporal responsiveness of the basolateral amygdala (BLA), ventral hippocampus (vHIP) and medial prefrontal cortex (mPFC) in this process. METHODS: Mouse models of acute social defeat were established by using the resident-intruder paradigm. To evaluate the engram of social defeat, the intruder mice were placed into the novel context at designated time to test the social behavior. Furthermore, responses of BLA, vHIP and mPFC were investigated by analyzing the expression of immediate early genes, such as zif268, arc, and c-fos. RESULTS: The results showed after an aggressive attack, aversive memory was maintained for approximately 7 days before gradually diminishing. The establishment and maintenance of aversive stimulation were consistently accompanied by BLA activity. By contrast, vHIP and mPFC response was inhibited from this process. Additionally, injecting muscimol (Mus), a GABA receptor agonist, into the BLA alleviated the freezing behavior and social fear and avoidance. Simultaneously, Mus treatment decreased the zif268 and arc expression in BLA, but it increased their expression in vHIP. CONCLUSION: Our data support and extend earlier findings that implicate BLA, vHIP and mPFC in social defeat. The time courses of the establishment and extinction of social defeat are particularly consistent with the contrasting BLA and vHIP responses involved in this process.


Asunto(s)
Complejo Nuclear Basolateral/metabolismo , Extinción Psicológica/fisiología , Miedo/fisiología , Hipocampo/metabolismo , Consolidación de la Memoria/fisiología , Corteza Prefrontal/metabolismo , Animales , Miedo/psicología , Genes Inmediatos-Precoces/fisiología , Masculino , Ratones , Ratones Endogámicos C57BL , Distribución Aleatoria , Conducta Social
11.
Lipids Health Dis ; 17(1): 42, 2018 Mar 09.
Artículo en Inglés | MEDLINE | ID: mdl-29523142

RESUMEN

BACKGROUND: The fibrillation of islet amyloid polypeptide (IAPP) triggered the amyloid deposition, then enhanced the loss of the pancreatic islet mass. However, it is not clear what factor is the determinant in development of the fibril formation. The aim of this study is to investigate the effects of lipid on IAPP fibril and its injury on pancreatic islet. METHODS: The fibril form of human IAPP (hIAPP) was tested using thioflavin-T fluorescence assay and transmission electron microscope technology after incubated with palmitate for 5 h at 25 °C. The cytotoxicity of fibril hIAPP was evaluated in INS-1 cells through analyzing the leakage of cell membrane and cell apoptosis. Type 2 diabetes mellitus (T2DM) animal model was induced with low dose streptozotocin combined the high-fat diet feeding for two months in rats. Plasma biochemistry parameters were measured before sacrificed. Pancreatic islet was isolated to evaluate their function. RESULTS: The results showed that co-incubation of hIAPP and palmitate induced more fibril form. Fibril hIAPP induced cell lesions including cell membrane leakage and cell apoptosis accompanied insulin mRNA decrease in INS-1 cell lines. In vivo, Plasma glucose, triglyceride, rIAPP and insulin increased in T2DM rats compared with the control group. In addition, IAPP and insulin mRNA increased in pancreatic islet of T2DM rats. Furthermore, T2DM induced the reduction of insulin receptor expression and cleaved caspase-3 overexpression in pancreatic islet. CONCLUSIONS: Results in vivo and in vitro suggested that lipid and IAPP plays a synergistic effect on pancreatic islet cell damage, which implicated in enhancing the IAPP expression and accelerating the fibril formation of IAPP.


Asunto(s)
Diabetes Mellitus Tipo 2/patología , Polipéptido Amiloide de los Islotes Pancreáticos/metabolismo , Islotes Pancreáticos/patología , Metabolismo de los Lípidos , Amiloide/metabolismo , Animales , Glucemia/metabolismo , Línea Celular Tumoral , Permeabilidad de la Membrana Celular/efectos de los fármacos , Diabetes Mellitus Experimental/metabolismo , Diabetes Mellitus Experimental/patología , Diabetes Mellitus Tipo 2/metabolismo , Dieta Alta en Grasa , Humanos , Resistencia a la Insulina , Insulinoma/patología , Polipéptido Amiloide de los Islotes Pancreáticos/farmacología , Islotes Pancreáticos/metabolismo , Masculino , Neoplasias Pancreáticas/patología , Ratas Sprague-Dawley , Estreptozocina
12.
Blood ; 126(10): 1224-33, 2015 Sep 03.
Artículo en Inglés | MEDLINE | ID: mdl-26209658

RESUMEN

Autophagy is important for maintaining cellular homeostasis, and thus its deficiency is implicated in a broad spectrum of human diseases. Its role in platelet function has only recently been examined. Our biochemical and imaging studies demonstrate that the core autophagy machinery exists in platelets, and that autophagy is constitutively active in resting platelets. Moreover, autophagy is induced upon platelet activation, as indicated by agonist-induced loss of the autophagy marker LC3II. Additional experiments, using inhibitors of platelet activation, proteases, and lysosomal acidification, as well as platelets from knockout mouse strains, show that agonist-induced LC3II loss is a consequence of platelet signaling cascades and requires proteases, acidic compartments, and membrane fusion. To assess the physiological role of platelet autophagy, we generated a mouse strain with a megakaryocyte- and platelet-specific deletion of Atg7, an enzyme required for LC3II production. Ex vivo analysis of platelets from these mice shows modest defects in aggregation and granule cargo packaging. Although these mice have normal platelet numbers and size distributions, they exhibit a robust bleeding diathesis in the tail-bleeding assay and a prolonged occlusion time in the FeCl3-induced carotid injury model. Our results demonstrate that autophagy occurs in platelets and is important for hemostasis and thrombosis.


Asunto(s)
Autofagia/fisiología , Hemostasis/fisiología , Activación Plaquetaria/fisiología , Trombosis/fisiopatología , Animales , Plaquetas/fisiología , Western Blotting , Células Cultivadas , Humanos , Ratones , Ratones Mutantes
13.
J Biol Chem ; 289(38): 26021-26037, 2014 Sep 19.
Artículo en Inglés | MEDLINE | ID: mdl-25086043

RESUMEN

Autophagy is a tightly regulated lysosomal degradation pathway for maintaining cellular homeostasis and responding to stresses. Beclin 1 and its interacting proteins, including the class III phosphatidylinositol-3 kinase Vps34, play crucial roles in autophagy regulation in mammals. We identified nuclear receptor binding factor 2 (Nrbf2) as a Beclin 1-interacting protein from Becn1(-/-);Becn1-EGFP/+ mouse liver and brain. We also found that Nrbf2-Beclin 1 interaction required the N terminus of Nrbf2. We next used the human retinal pigment epithelial cell line RPE-1 as a model system and showed that transiently knocking down Nrbf2 by siRNA increased autophagic flux under both nutrient-rich and starvation conditions. To investigate the mechanism by which Nrbf2 regulates autophagy, we demonstrated that Nrbf2 interacted and colocalized with Atg14L, suggesting that Nrbf2 is a component of the Atg14L-containing Beclin 1-Vps34 complex. Moreover, ectopically expressed Nrbf2 formed cytosolic puncta that were positive for isolation membrane markers. These results suggest that Nrbf2 is involved in autophagosome biogenesis. Furthermore, we showed that Nrbf2 deficiency led to increased intracellular phosphatidylinositol-3 phosphate levels and diminished Atg14L-Vps34/Vps15 interactions, suggesting that Nrbf2-mediated Atg14L-Vps34/Vps15 interactions likely inhibit Vps34 activity. Therefore, we propose that Nrbf2 may interact with the Atg14L-containing Beclin 1-Vps34 protein complex to modulate protein-protein interactions within the complex, leading to suppression of Vps34 activity, autophagosome biogenesis, and autophagic flux. This work reveals a novel aspect of the intricate mechanism for the Beclin 1-Vps34 protein-protein interaction network to achieve precise control of autophagy.


Asunto(s)
Proteínas Adaptadoras del Transporte Vesicular/metabolismo , Proteínas Reguladoras de la Apoptosis/metabolismo , Autofagia , Fosfatidilinositol 3-Quinasas Clase III/metabolismo , Proteínas de la Membrana/metabolismo , Fosfatos de Fosfatidilinositol/metabolismo , Transactivadores/fisiología , Secuencia de Aminoácidos , Proteínas Relacionadas con la Autofagia , Beclina-1 , Proteínas Fluorescentes Verdes/biosíntesis , Células Hep G2 , Humanos , Datos de Secuencia Molecular , Complejos Multiproteicos/metabolismo , Fagosomas/metabolismo , Unión Proteica , Dominios y Motivos de Interacción de Proteínas , Mapas de Interacción de Proteínas , Transporte de Proteínas , Proteínas Recombinantes de Fusión/biosíntesis , Transactivadores/química
14.
BMC Cardiovasc Disord ; 14: 83, 2014 Jul 14.
Artículo en Inglés | MEDLINE | ID: mdl-25022285

RESUMEN

BACKGROUND: Statin therapy has shown to deplete atherosclerotic plaque lipid content and induce plaque regression. However, how early the plaque lipid depletion can occur with low-density lipoprotein cholesterol (LDL-C) lowering in humans in vivo has not been fully described. METHODS: We enrolled 43 lipid treatment naïve subjects with asymptomatic carotid atherosclerosis and LDL-C ≥ 100 and ≤ 250 mg/dl. Rosuvastatin 5-20 mg/day was used to lower LDL-C levels to < 80 mg/dl. Lipid profile and carotid MRI scans were obtained at baseline, 3, 12, and 24 months. Carotid plaque lipid-rich necrotic core (LRNC) and plaque burden were measured and compared between baseline and during treatment. RESULTS: Among the 32 subjects who completed the study, at 3 months, an average dose of rosuvastatin of 11 mg/day lowered LDL-C levels by 47% (125.2 ± 24.4 mg/dl vs. 66.7 ± 17.3 mg/dl, p < 0.001). There were no statistically significant changes in total wall volume, percent wall volume or lumen volume. However, LRNC volume was significantly decreased by 7.9 mm3, a reduction of 7.3% (111.5 ± 104.2 mm3 vs. 103.6 ± 95.8 mm3, p = 0.044). Similarly, % LRNC was also significantly decreased from 18.9 ± 11.9% to 17.9 ± 11.5% (p = 0.02) at 3 months. Both LRNC volume and % LRNC continued to decrease moderately at 12 and 24 months, although this trend was not significant. CONCLUSIONS: Among a small number of lipid treatment naïve subjects, rosuvastatin therapy may induce a rapid and lasting decrease in carotid plaque lipid content as assessed by MRI. TRIAL REGISTRATION: ClinicalTrials.Gov numbers NCT00885872.


Asunto(s)
Enfermedades de las Arterias Carótidas/tratamiento farmacológico , Arteria Carótida Común/efectos de los fármacos , LDL-Colesterol/sangre , Fluorobencenos/uso terapéutico , Inhibidores de Hidroximetilglutaril-CoA Reductasas/uso terapéutico , Imagen por Resonancia Magnética , Placa Aterosclerótica , Pirimidinas/uso terapéutico , Sulfonamidas/uso terapéutico , Anciano , Enfermedades Asintomáticas , Biomarcadores/sangre , Enfermedades de las Arterias Carótidas/sangre , Enfermedades de las Arterias Carótidas/diagnóstico , Arteria Carótida Común/metabolismo , Arteria Carótida Común/patología , China , Femenino , Humanos , Masculino , Persona de Mediana Edad , Necrosis , Valor Predictivo de las Pruebas , Estudios Prospectivos , Rosuvastatina Cálcica , Factores de Tiempo , Resultado del Tratamiento
15.
Aging (Albany NY) ; 16(16): 12050-12062, 2024 Aug 23.
Artículo en Inglés | MEDLINE | ID: mdl-39181688

RESUMEN

Eosinophils have the potential to exhibit both anti-tumor properties and tumor-promoting effects. However, the impact of eosinophil levels in the bloodstream on tumorigenesis risk remains inadequately explored. Furthermore, investigations regarding the association between drugs regulating eosinophils and cancer risk are currently absent. In this study, we conducted a Mendelian randomization (MR) analysis utilizing eosinophil count and eosinophil percentage as exposures. In both cohorts, a significant association was observed between eosinophil count and the risk of colorectal cancer and skin malignancies. However, upon conducting a sensitivity analysis, heterogeneity was detected specifically in relation to skin malignancies. Subsequent reverse Mendelian randomization analysis did not indicate any evidence of reverse causality. Furthermore, the multivariate Mendelian randomization analysis results suggested that eosinophils act as a mediating factor in reducing the risk of colorectal cancer and skin malignancies in individuals with asthma. And the use of drugs that modulate eosinophilia may increase the risk of colorectal cancer. It is evident that the statistical evidence supporting a negative correlation between eosinophils count and the susceptibility to colorectal cancer is particularly robust. And, it is plausible to suggest that pharmaceutical interventions aimed at modulating eosinophilia may potentially heighten the risk of colorectal cancer. Hence, it is imperative to exercise caution and remain mindful of the potential risk of colorectal cancer when employing these medications.


Asunto(s)
Neoplasias Colorrectales , Eosinofilia , Eosinófilos , Análisis de la Aleatorización Mendeliana , Humanos , Neoplasias Colorrectales/genética , Neoplasias Colorrectales/epidemiología , Eosinofilia/genética , Eosinofilia/epidemiología , Recuento de Leucocitos , Factores de Riesgo
16.
Biochim Biophys Acta ; 1817(5): 792-801, 2012 May.
Artículo en Inglés | MEDLINE | ID: mdl-22266340

RESUMEN

Oxygenic photosynthesis in cyanobacteria, algae, and plants requires photosystem II (PSII) to extract electrons from H(2)O and depends on photosystem I (PSI) to reduce NADP(+). Here we demonstrate that mixotrophically-grown mutants of the cyanobacterium Synechocystis sp. PCC 6803 that lack PSI (ΔPSI) are capable of net light-induced O(2) evolution in vivo. The net light-induced O(2) evolution requires glucose and can be sustained for more than 30 min. Utilizing electron transport inhibitors and chlorophyll a fluorescence measurements, we show that in these mutants PSII is the source of the light-induced O(2) evolution, and that the plastoquinone pool is reduced by PSII and subsequently oxidized by an unidentified electron acceptor that does not involve the plastoquinol oxidase site of the cytochrome b(6)f complex. Moreover, both O(2) evolution and chlorophyll a fluorescence kinetics of the ΔPSI mutants are highly sensitive to KCN, indicating the involvement of a KCN-sensitive enzyme(s). Experiments using (14)C-labeled bicarbonate show that the ΔPSI mutants assimilate more CO(2) in the light compared to the dark. However, the rate of the light-minus-dark CO(2) assimilation accounts for just over half of the net light-induced O(2) evolution rate, indicating the involvement of unidentified terminal electron acceptors. Based on these results we suggest that O(2) evolution in ΔPSI cells can be sustained by an alternative electron transport pathway that results in CO(2) assimilation and that includes PSII, the platoquinone pool, and a KCN-sensitive enzyme.


Asunto(s)
Eliminación de Gen , Luz , Oxígeno/metabolismo , Complejo de Proteína del Fotosistema I/genética , Synechocystis/metabolismo , Dióxido de Carbono/metabolismo , Respiración de la Célula/efectos de los fármacos , Respiración de la Célula/efectos de la radiación , Clorofila/metabolismo , Clorofila A , Complejo de Citocromo b6f/metabolismo , Oscuridad , Dibromotimoquinona/farmacología , Diurona/farmacología , Fluorescencia , Glucosa/farmacología , Cinética , Oxidación-Reducción/efectos de los fármacos , Oxidación-Reducción/efectos de la radiación , Complejo de Proteína del Fotosistema I/metabolismo , Complejo de Proteína del Fotosistema II/metabolismo , Plastoquinona/metabolismo , Cianuro de Potasio/farmacología , Bicarbonato de Sodio/farmacología , Análisis Espectral , Synechocystis/efectos de los fármacos , Synechocystis/efectos de la radiación
17.
Res Pract Thromb Haemost ; 6(5): e12755, 2022 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-35873218

RESUMEN

Background: Platelet-fibrin clot contraction is critical for wound closure and maintenance of vessel patency, yet a molecular understanding of the process has lagged because of a lack of flexible quantitative assay systems capable of assaying multiple samples simultaneously. Objectives: We devised a sensitive and inexpensive method to assess clot contraction kinetics under multiple conditions. Methods: Clot contraction was measured using time-lapse digital photography, automated image processing with customized software, and detailed kinetic analysis using available commercial programs. Results: Our system was responsive to alterations in platelet counts and calcium, fibrinogen, and thrombin concentrations, and our analysis detected and defined three phases of platelet-fibrin clot formation: initiation, contraction, and stabilization. Lag time, average contraction velocity, contraction extent, and area under the curve were readily calculated from the data. Using pharmacological agents (blebbistatin and eptifibatide), we confirmed the importance of myosin IIA and the interactions of integrin αIIbß3-fibrinogen/fibrin in clot contraction. As further proof of our system's utility, we showed how 2-deoxyglucose affects contraction, demonstrating the importance of platelet bioenergetics, specifically glycolysis. Conclusions: Our system is an adaptable platform for assessing the effects of multiple conditions and interventions on clot contraction kinetics in a regular laboratory setting, using readily available materials. The automated image processing software we developed will be made freely available for noncommercial uses. This assay system can be used to directly compare and define the effects of different treatments or genetic manipulations on platelet function and should provide a robust tool for future hemostasis/thrombosis research and therapeutic development.

18.
Ann Transl Med ; 10(6): 353, 2022 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-35434038

RESUMEN

Background: Recent studies have shown that pyroptosis is related to cancer development. Our previous study also found that gasdermins (GSDMs) was associated with the tumor immune microenvironment. Therefore, we wanted to observe the relationship between pyroptosis and the immune microenvironment and prognosis of skin cutaneous melanoma (SKCM). Methods: Pyroptosis-related genes were used for pan-cancer prognostic analysis using the GEPIA2 online analysis website. Prognosis-related genes were clustered using R software and related R packages, and the best clustering results were screened for prognosis analysis. The prognosis-related genes were also used to establish a prognosis-related model. Assess the predictive power of a model by comparing area under the curve (AUC). The t-test was used to analyze the differences of immune-related indicators between the two clusters and between high and low risk groups. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis was performed on the differential genes. Results: By clustering the prognosis-related genes, SKCM could be divided into 2 clusters with significant differences in prognosis P<0.05. A prognostic model can be established using prognosis-related genes. The AUC value of 1 year, 2 years and 3 years was 0.696, 0.702 and 0.664, respectively. The risk score was significantly associated with prognosis in both univariate and multivariate Cox analyses P<0.001. The low-risk group or C2 cluster with better prognosis had higher expression of pyroptosis-related genes, and tended to have a lower exclusion score, greater chemokine expression, more immune cells and higher immune score. However, the C2 cluster or low-risk group was also associated with a higher dysfunction score. At the same time, the C2 or low-risk group was more suitable for immunotherapy because of the higher immunophenoscore (IPS) score P<0.001. Correlation analysis also demonstrated that the risk score was positively correlated with the gene expression of most immunoinhibitors, MHC molecules, immunostimulators, and chemokines and their receptors. Conclusions: Pyroptosis is associated with melanoma immune microenvironment, immunotherapy response, and prognoses. The constructed risk scores could effectively predict the characteristics of the immune microenvironment, the sensitivity to immunotherapy, and the prognosis of melanoma patients.

19.
Mitochondrial DNA B Resour ; 6(3): 990-992, 2021 Mar 18.
Artículo en Inglés | MEDLINE | ID: mdl-33796711

RESUMEN

Ipomoea aquatica, commonly known as water spinach, is an edible annual vegetable in the genus Ipomoea,. In this study, the complete plastome of Ipomoea aquatica was determined using the Illumina sequencing platform. The plastome size was 162,663 bp. It consists of four regions, including a large single-copy region (88,166 bp), a small single-copy region (12,069 bp), and a pair of inverted repeat regions (31,214 bp). This plastome encodes 114 unique genes, including 80 protein-coding genes (PCGs), 30 transfer RNA genes (tRNAs), and 4 ribosomal RNA genes (rRNAs). The GC content was 39.1%. Phylogenomic analysis based on 19 complete plastomes revealed that I. aquatica was closely related to I. diamantinensis.

20.
Eur J Radiol ; 143: 109912, 2021 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-34450516

RESUMEN

PURPOSE: This study aims to compare the diagnostic performance of two imaging methods for thyroid nodules ≤1.0 cm and reduce unnecessary overdiagnosis. METHODS: A retrospective study was conducted on 80 patients with pathologically confirmed solitary thyroid micronodules underwent both high-resolution ultrasound (HRUS) and High b-value (2000 s/mm2) diffusion weighted imaging (DWI). Intra- and interobserver agreement (Intraclass correlation coefficient) was followed by Kruskal-Wallis test to detect whether the quantitative apparent diffusion coefficient (ADC) and thyroid nodule subgroups were related. Cohen's kappa analysis was applied to assess the interobserver consistency of DWI and HRUS characteristics. The receiver operating characteristic curves were adopted for evaluating the diagnostic performance of thyroid malignancy. The sensitivity, specificity, and accuracy of the two imaging methods were compared using the McNemar's test and Kappa test. RESULTS: A total of 80 patients were included, consisting of 43 malignant and 37 benign micronodules. The sensitivity, specificity and accuracy of DWI combined with rADC (ADCmin to ADCn ratio) for the diagnosis of thyroid micronodules were 83.7%, 89.2% and 86.3%, respectively. The area under the curve (AUC) was 0.91 (95% confidence interval [CI]: 0.84-0.97). The sensitivity, specificity and accuracy of HRUS diagnosis were 100%, 62.16% and 82.5%, respectively. CONCLUSION: High b-value DWI is superior to HRUS for evaluating the diagnostic performance of solid thyroid micronodules. DWI and its ADC quantitative analysis could be added to the evaluation of thyroid micronodules to improve the specificity of diagnosis, reduce overdiagnosis and avoid unnecessary biopsies or surgeries.


Asunto(s)
Imagen de Difusión por Resonancia Magnética , Glándula Tiroides , Diagnóstico Diferencial , Humanos , Curva ROC , Reproducibilidad de los Resultados , Estudios Retrospectivos , Sensibilidad y Especificidad , Glándula Tiroides/diagnóstico por imagen
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