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BACKGROUND: Exercise intolerance is an independent predictor of poor prognosis in diabetes. The underlying mechanism of the association between hyperglycemia and exercise intolerance remains undefined. We recently demonstrated that the interaction between ARRDC4 (arrestin domain-containing protein 4) and GLUT1 (glucose transporter 1) regulates cardiac metabolism. METHODS: To determine whether this mechanism broadly impacts diabetic complications, we investigated the role of ARRDC4 in the pathogenesis of diabetic cardiac/skeletal myopathy using cellular and animal models. RESULTS: High glucose promoted translocation of MondoA into the nucleus, which upregulated Arrdc4 transcriptional expression, increased lysosomal GLUT1 trafficking, and blocked glucose transport in cardiomyocytes, forming a feedback mechanism. This role of ARRDC4 was confirmed in human muscular cells from type 2 diabetic patients. Prolonged hyperglycemia upregulated myocardial Arrdc4 expression in multiple types of mouse models of diabetes. We analyzed hyperglycemia-induced cardiac and skeletal muscle abnormalities in insulin-deficient mice. Hyperglycemia increased advanced glycation end-products and elicited oxidative and endoplasmic reticulum stress leading to apoptosis in the heart and peripheral muscle. Deletion of Arrdc4 augmented tissue glucose transport and mitochondrial respiration, protecting the heart and muscle from tissue damage. Stress hemodynamic analysis and treadmill exhaustion test uncovered that Arrdc4-knockout mice had greater cardiac inotropic/chronotropic reserve with higher exercise endurance than wild-type animals under diabetes. While multiple organs were involved in the mechanism, cardiac-specific overexpression using an adenoassociated virus suggests that high levels of myocardial ARRDC4 have the potential to contribute to exercise intolerance by interfering with cardiac metabolism through its interaction with GLUT1 in diabetes. Importantly, the ARRDC4 mutation mouse line exhibited greater exercise tolerance, showing the potential therapeutic impact on diabetic cardiomyopathy by disrupting the interaction between ARRDC4 and GLUT1. CONCLUSIONS: ARRDC4 regulates hyperglycemia-induced toxicities toward cardiac and skeletal muscle, revealing a new molecular framework that connects hyperglycemia to cardiac/skeletal myopathy to exercise intolerance.
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Tolerancia al Ejercicio , Transportador de Glucosa de Tipo 1 , Ratones Noqueados , Animales , Humanos , Masculino , Ratones , Células Cultivadas , Diabetes Mellitus Experimental/metabolismo , Diabetes Mellitus Experimental/genética , Diabetes Mellitus Tipo 2/metabolismo , Diabetes Mellitus Tipo 2/genética , Cardiomiopatías Diabéticas/metabolismo , Cardiomiopatías Diabéticas/genética , Cardiomiopatías Diabéticas/fisiopatología , Cardiomiopatías Diabéticas/etiología , Transportador de Glucosa de Tipo 1/genética , Transportador de Glucosa de Tipo 1/metabolismo , Hiperglucemia/metabolismo , Hiperglucemia/genética , Ratones Endogámicos C57BL , Músculo Esquelético/metabolismo , Miocitos Cardíacos/metabolismoRESUMEN
In mammals, primordial germ cells (PGCs), the origin of the germ line, are specified from the epiblast at the posterior region where gastrulation simultaneously occurs, yet the functional relationship between PGC specification and gastrulation remains unclear. Here, we show that OVOL2, a transcription factor conserved across the animal kingdom, balances these major developmental processes by repressing the epithelial-to-mesenchymal transition (EMT) that drives gastrulation and the upregulation of genes associated with PGC specification. Ovol2a, a splice variant encoding a repressor domain, directly regulates EMT-related genes and, consequently, induces re-acquisition of potential pluripotency during PGC specification, whereas Ovol2b, another splice variant missing the repressor domain, directly upregulates genes associated with PGC specification. Taken together, these results elucidate the molecular mechanism underlying allocation of the germ line among epiblast cells differentiating into somatic cells through gastrulation. This article has an associated 'The people behind the papers' interview.
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Desarrollo Embrionario/genética , Gastrulación/genética , Células Germinativas/metabolismo , Factores de Transcripción/metabolismo , Animales , Cadherinas/genética , Cadherinas/metabolismo , Linaje de la Célula , Embrión de Mamíferos/citología , Embrión de Mamíferos/metabolismo , Transición Epitelial-Mesenquimal/genética , Femenino , Células Germinativas/citología , Ratones , Ratones Endogámicos C57BL , Ratones Noqueados , Factor 1 de Unión al Dominio 1 de Regulación Positiva/genética , Factor 1 de Unión al Dominio 1 de Regulación Positiva/metabolismo , Isoformas de Proteínas/genética , Isoformas de Proteínas/metabolismo , Factores de Transcripción/deficiencia , Factores de Transcripción/genética , Regulación hacia Arriba , Homeobox 1 de Unión a la E-Box con Dedos de Zinc/genética , Homeobox 1 de Unión a la E-Box con Dedos de Zinc/metabolismoRESUMEN
Activation of pyruvate dehydrogenase (PDH) by inhibition of pyruvate dehydrogenase kinase (PDHK) has the potential for the treatment of diabetes mellitus and its complications, caused by the malfunction of the glycolytic system and glucose oxidation. In this paper, we describe the identification of novel PDHK inhibitors with a fluorene structure. High-throughput screening using our in-house library provided compound 6 as a weak inhibitor that occupied the allosteric lipoyl group binding site in PDHK2. Structure-based drug design (SBDD) while addressing physicochemical properties succeeded in boosting inhibitory activity approximately 700-fold. Thus obtained compound 32 showed favorable pharmacokinetics profiles supported by high membrane permeability and metabolic stability, and exhibited activation of PDH in rat livers and a glucose lowering effect in Zucker fatty rats.
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Diseño de Fármacos , Fluorenos , Inhibidores de Proteínas Quinasas , Proteínas Serina-Treonina Quinasas , Piruvato Deshidrogenasa Quinasa Acetil-Transferidora , Ratas Zucker , Animales , Piruvato Deshidrogenasa Quinasa Acetil-Transferidora/antagonistas & inhibidores , Piruvato Deshidrogenasa Quinasa Acetil-Transferidora/metabolismo , Ratas , Fluorenos/química , Fluorenos/síntesis química , Fluorenos/farmacología , Relación Estructura-Actividad , Inhibidores de Proteínas Quinasas/farmacología , Inhibidores de Proteínas Quinasas/síntesis química , Inhibidores de Proteínas Quinasas/química , Proteínas Serina-Treonina Quinasas/antagonistas & inhibidores , Proteínas Serina-Treonina Quinasas/metabolismo , Estructura Molecular , Humanos , Relación Dosis-Respuesta a DrogaRESUMEN
n-3 polyunsaturated fatty acids (n-3 PUFAs), including α-linolenic acid and eicosapentaenoic acid (EPA), are essential nutrients for vertebrates including humans. Vertebrates are n-3 PUFA-auxotrophic; hence, dietary intake of n-3 PUFAs is required for their normal physiology and development. Although fish meal and oil have been utilized as primary sources of n-3 PUFAs by humans and aquaculture, these traditional n-3 PUFA sources are expected to be exhausted because of the increasing consumption requirements of humans. Hence, it is necessary to establish alternative n-3 PUFA sources to reduce the gap between the supply and demand of n-3 PUFAs. Here, we investigated whether insects, which are considered as a novel source of essential nutrients, could store n-3 PUFAs by the forced expression of n-3 PUFA biosynthetic enzymes. We utilized Drosophila as an insect model to generate transgenic strains expressing Caenorhabditis elegans PUFA biosynthetic enzymes and examined their effects on the proportion of fatty acids. The ubiquitous expression of methyl-end desaturase FAT-1 prominently enhanced the proportions of α-linolenic acid, indicating that FAT-1 is useful for metabolic engineering to fortify α-linolenic acid in insect. Furthermore, the ubiquitous expression of nematode front-end desaturases (FAT-3 and FAT-4), PUFA elongase (ELO-1), and FAT-1 led to EPA bioproduction. Hence, nematode PUFA biosynthetic genes may serve as powerful genetic tools for enhancing the proportion of EPA in insects. This study represents the first step toward the establishment of n-3 PUFA-producing insects.
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Ácidos Grasos Omega-3 , Animales , Humanos , Ácidos Grasos Omega-3/genética , Ácido Graso Desaturasas/genética , Ácido Graso Desaturasas/metabolismo , Drosophila melanogaster/genética , Drosophila melanogaster/metabolismo , Elongasas de Ácidos Grasos/genética , Ácido alfa-Linolénico , Ácidos Grasos , Caenorhabditis elegans/genética , Caenorhabditis elegans/metabolismoRESUMEN
ABSTRACT: Binge drinking is a risk factor for cardiac arrhythmias, known as the holiday heart syndrome. Atrial fibrillation (AF) is the most frequently diagnosed arrhythmia in this condition. Recent reports indicated that cardiac ryanodine receptor (RyR2) dysfunction and Ca 2+ leak contribute to alcohol-enhanced AF. In this study, we investigated whether stabilizing RyR2 with dantrolene treatment can prevent alcohol-enhanced AF in rats. A binge drinking rat model was established with alcohol (2 g /kg, IP) delivered once every other day for 4 times. The study consisted of following 3 groups: control group (n = 9), binge alcohol group (n = 10), and binge alcohol + dantrolene (A+D) group (dantrolene, 10 mg/kg, IP before each alcohol injection, n = 9). Echocardiography, left ventricular hemodynamics, in vivo atrial electrophysiology and AF inducibility test, RyR2 phosphorylation level, and blood norepinephrine level were studied 24 hours after the last injection. Ca 2+ leak in isolated atrial myocytes from control and binge alcohol rats was examined. Binge alcohol significantly increased AF inducibility (1/9 in control vs. 8/9 in binge alcohol group, P < 0.05) and AF duration. Dantrolene treatment significantly reduced both AF inducibility (2/9 in dantrolene group, P < 0.05) and AF duration. Binge alcohol significantly increased Ca 2+ leak in isolated atrial myocytes, which was reduced by dantrolene treatment. Blood norepinephrine,7 RyR2 phosphorylation level, cardiac echocardiography, and left ventricular hemodynamics were not significantly affected 24 hours after binge drinking. In conclusion, stabilizing RyR2 with dantrolene treatment significantly attenuated binge drinking-enhanced AF, suggesting that therapeutic strategies stabilizing RyR2 could be a preventive measure to blunt binge drinking-enhanced AF arrhythmogenesis.
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Fibrilación Atrial , Consumo Excesivo de Bebidas Alcohólicas , Ratas , Animales , Dantroleno/farmacología , Canal Liberador de Calcio Receptor de Rianodina , Fibrilación Atrial/tratamiento farmacológico , Fibrilación Atrial/etiología , Fibrilación Atrial/prevención & control , Consumo Excesivo de Bebidas Alcohólicas/complicaciones , Atrios Cardíacos/metabolismo , Miocitos Cardíacos/metabolismo , Etanol , Norepinefrina , Calcio/metabolismo , Retículo Sarcoplasmático/metabolismoRESUMEN
Late rather than acute kidney injury after percutaneous coronary intervention (PCI) has been recently recognized as a predictor of future adverse events in patient with coronary artery disease. The risk-predicting models for acute kidney injury reported by Mehran et al., Bartholomew et al., and Tsai et al. were derived from a large cohort and externally validated, although the applicability of these models for predicting late kidney injury is unknown. A total of 327 patients undergoing elective PCI procedures were included. We calculated the three scores and tested their diagnostic ability for predicting late kidney injury (> 6 months after PCI), defined as an increase in creatinine levels ≥ 0.3 mg/dl or ≥ 50% from baseline. During the median follow-up period of 28 months, 27 (8.3%) patients had late kidney injury. All three scores significantly predicted late kidney injury, among which the score by Tsai et al. had a better diagnostic ability (area under the curve 0.83, best cut-off value 14, p < 0.001). With the best cut-off value, patients with Tsai score ≥ 14 had a significantly higher rate of late kidney injury than their counterpart (27.4% vs. 2.8%, p < 0.001). In conclusion, established risk scores for acute kidney injury may be useful for predicting late kidney injury after PCI in patients with chronic coronary syndrome.
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Síndrome Coronario Agudo , Lesión Renal Aguda , Intervención Coronaria Percutánea , Humanos , Intervención Coronaria Percutánea/efectos adversos , Intervención Coronaria Percutánea/métodos , Creatinina , Medios de Contraste/efectos adversos , Medición de Riesgo/métodos , Lesión Renal Aguda/diagnóstico , Lesión Renal Aguda/epidemiología , Lesión Renal Aguda/etiología , Riñón , Factores de Riesgo , Síndrome Coronario Agudo/complicaciones , Síndrome Coronario Agudo/diagnóstico , Síndrome Coronario Agudo/terapiaRESUMEN
Some drugs with carboxylic acid moieties can potentially cause rare but severe hepatotoxicity. The reactive chemical species generated by drug metabolism are thought to be one reason for this event. Although the phase II conjugation metabolism of carboxylic acids generally renders a compound more polar and inactive, it is also responsible for the formation of reactive metabolites.This study aimed to provide a new approach towards the risk assessment of carboxylic acids in the aspect of reactive acyl CoA metabolites.Although acyl CoA metabolites have been concerned, it is difficult to detect them because of their instability. We investigated the trapping agents for acyl CoA metabolites. We found that cysteine is a good trapping agent and developed an assay method for the reactivity of acyl CoA metabolites. We evaluated 17 drugs with carboxylic acid moieties, all drugs concerned with hepatotoxicity displayed reactive potential. With consideration of the exposure of each parent drug, the correlation between drug labels and the calculated risk of carboxylic drugs was improved.These evaluations can be conducted without radiochemical reagents or the authentic standards of metabolites. We believe that the method will be beneficial for drug discovery.
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Acilcoenzima A , Efectos Colaterales y Reacciones Adversas Relacionados con Medicamentos , Acilcoenzima A/química , Acilcoenzima A/metabolismo , Ácidos Carboxílicos/metabolismo , Cisteína , Humanos , Medición de RiesgoRESUMEN
Repression of somatic gene expression in germline progenitors is one of the critical mechanisms involved in establishing the germ/soma dichotomy. In Drosophila, the maternal Nanos (Nos) and Polar granule component (Pgc) proteins are required for repression of somatic gene expression in the primordial germ cells, or pole cells. Pgc suppresses RNA polymerase II-dependent global transcription in pole cells, but it remains unclear how Nos represses somatic gene expression. Here, we show that Nos represses somatic gene expression by inhibiting translation of maternal importin-α2 (impα2) mRNA. Mis-expression of Impα2 caused aberrant nuclear import of a transcriptional activator, Ftz-F1, which in turn activated a somatic gene, fushi tarazu (ftz), in pole cells when Pgc-dependent transcriptional repression was impaired. Because ftz expression was not fully activated in pole cells in the absence of either Nos or Pgc, we propose that Nos-dependent repression of nuclear import of transcriptional activator(s) and Pgc-dependent suppression of global transcription act as a 'double-lock' mechanism to inhibit somatic gene expression in germline progenitors.
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Proteínas de Drosophila/genética , Drosophila melanogaster/genética , Proteínas Nucleares/genética , Óvulo/metabolismo , Proteínas de Unión al ARN/genética , Espermatozoides/metabolismo , alfa Carioferinas/genética , Transporte Activo de Núcleo Celular , Animales , Proteínas de Unión al ADN/genética , Proteínas de Unión al ADN/metabolismo , Proteínas de Drosophila/metabolismo , Drosophila melanogaster/citología , Drosophila melanogaster/crecimiento & desarrollo , Drosophila melanogaster/metabolismo , Femenino , Factores de Transcripción Fushi Tarazu/genética , Factores de Transcripción Fushi Tarazu/metabolismo , Regulación del Desarrollo de la Expresión Génica , Masculino , Proteínas Nucleares/metabolismo , Ovario/citología , Ovario/crecimiento & desarrollo , Ovario/metabolismo , Óvulo/citología , Factor B de Elongación Transcripcional Positiva/genética , Factor B de Elongación Transcripcional Positiva/metabolismo , ARN Polimerasa II/genética , ARN Polimerasa II/metabolismo , Proteínas de Unión al ARN/metabolismo , Espermatozoides/citología , Testículo/citología , Testículo/crecimiento & desarrollo , Testículo/metabolismo , Factores de Transcripción/genética , Factores de Transcripción/metabolismo , Transcripción Genética , alfa Carioferinas/metabolismoRESUMEN
Social insects often exhibit striking altruistic behaviors, of which the most spectacular ones may be self-destructive defensive behaviors called autothysis, "self-explosion," or "suicidal bombing." In the social aphid Nipponaphis monzeni, when enemies damage their plant-made nest called the gall, soldier nymphs erupt to discharge a large amount of body fluid, mix the secretion with their legs, and skillfully plaster it over the plant injury. Dozens of soldiers come out, erupt, mix, and plaster, and the gall breach is promptly sealed with the coagulated body fluid. What molecular and cellular mechanisms underlie the self-sacrificing nest repair with body fluid for the insect society? Here we demonstrate that the body cavity of soldier nymphs is full of highly differentiated large hemocytes that contain huge amounts of lipid droplets and phenoloxidase (PO), whereas their hemolymph accumulates huge amounts of tyrosine and a unique repeat-containing protein (RCP). Upon breakage of the gall, soldiers gather around the breach and massively discharge the body fluid. The large hemocytes rupture and release lipid droplets, which promptly form a lipidic clot, and, concurrently, activated PO converts tyrosine to reactive quinones, which cross-link RCP and other macromolecules to physically reinforce the clot to seal the gall breach. Here, soldiers' humoral and cellular immune mechanisms for wound sealing are extremely up-regulated and utilized for colony defense, which provides a striking case of direct evolutionary connection between individual immunity and social immunity and highlights the importance of exaggeration and cooption of preexisting traits to create evolutionary novelties.
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Áfidos/inmunología , Hemolinfa/inmunología , Inmunidad Innata/inmunología , Animales , Conducta Animal , Evolución Biológica , Hemocitos/inmunología , Insectos , Conducta SocialRESUMEN
The number of lung transplantation performed in Japan is extremely low compared to other countries, whereas we have 10 facilities certified as cadaveric lung transplantation in Japan, meaning that there are low volume centers. By August 2021, we performed lung transplantation in 21 cases for 12 years, therefore, our facility should be considered as low volume center. Surgical outcomes at low volume centers are generally considered poor. However, the overall five-year survival rate of total cases was 84.8%, and that of cadaveric cases was 94.4% in our hospital. It was better than the average of about 73% of all facilities in Japan. These data suggested that the accreditation system in Japan is functioning well. On the other hand, there may be a disparity between facilities. At our facility, we are actively performing inverted lung transplantation so as not to lose the opportunity for transplantation, and we have performed it in three cases so far and have achieved good results.
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Trasplante de Pulmón , Certificación , Humanos , Japón , Estudios Retrospectivos , Tasa de SupervivenciaRESUMEN
The Drosophila female germline stem cell (GSC) niche provides an excellent model for understanding the stem cell niche in vivo. The GSC niche is composed of stromal cells that provide growth factors for the maintenance of GSCs and the associated extracellular matrix (ECM). Although the function of stromal cells/growth factors has been well studied, the function of the ECM in the GSC niche is largely unknown. In this study, we investigated the function of syndecan and perlecan, molecules of the heparan sulfate proteoglycan (HSPG) family, as the main constituents of the ECM. We found that both of these genes were expressed in niche stromal cells, and knockdown of them in stromal cells decreased GSC number, indicating that these genes are important niche components. Interestingly, our genetic analysis revealed that the effects of syndecan and perlecan on the maintenance of GSC were distinct. While the knockdown of perlecan in the GSC niche increased the number of cystoblasts, a phenotype suggestive of delayed differentiation of GSCs, the same was not true in the context of syndecan. Notably, the overexpression of syndecan and perlecan did not cause an expansion of the GSC niche, opposing the results reported in the context of glypican, another HSPG gene. Altogether, our data suggest that HSPG genes contribute to the maintenance of GSCs through multiple mechanisms, such as the control of signal transduction, and ligand distribution/stabilization. Therefore, our study paves the way for a deeper understanding of the ECM functions in the stem cell niche.
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Drosophila , Proteoglicanos de Heparán Sulfato , Animales , Células Germinativas , Proteoglicanos de Heparán Sulfato/genética , Células Madre , Sindecanos/genéticaRESUMEN
Acute kidney injury usually assessed within 48 h after percutaneous coronary intervention (PCI) is associated with poor clinical outcomes, and persistent kidney damage is also strongly related to long-term mortality. However, little is known about longitudinal renal function change from a very early period to long-term follow-up after PCI. A total of 327 patients with stable coronary artery disease underwent elective PCI. Renal function was assessed with serum creatinine levels and estimated glomerular filtration rate (eGFR) at baseline, 1 day after PCI, at 1 year and at the latest follow-up. Kidney injury was defined as an increase in creatinine levels ≥ 0.3 mg/dl or ≥ 50% from baseline at each timepoint. Major adverse cardiovascular events (MACE) was defined as a composite of death, myocardial infarction, and stroke. eGFR was significantly increased 1 day after PCI, while it was progressively decreased at 1-year and long-term follow-up (median 28 months). Overall, eGFR was declined by - 2.3 ml/min/1.73 m2 per year. Only one (0.3%) patient developed kidney injury 1 day after PCI, whereas kidney injury at 1-year and long-term follow-up was observed in 15 (4.6%) and 27 (8.3%). During the follow-up period, 23 (7.0%) patients had MACE. The incidence of subsequent MACE was significantly higher in patients with kidney injury at 1 year than those without. In conclusion, kidney injury within 24 h after elective PCI was rarely observed. eGFR was progressively decreased over time, and mid-term kidney injury at 1 year was associated with future MACE.
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Lesión Renal Aguda/etiología , Enfermedad de la Arteria Coronaria/cirugía , Tasa de Filtración Glomerular/fisiología , Riñón/fisiopatología , Intervención Coronaria Percutánea/efectos adversos , Lesión Renal Aguda/diagnóstico , Lesión Renal Aguda/epidemiología , Anciano , Biomarcadores/sangre , Angiografía Coronaria , Creatinina/sangre , Femenino , Estudios de Seguimiento , Humanos , Incidencia , Japón/epidemiología , Masculino , Estudios Retrospectivos , Factores de Riesgo , Tasa de Supervivencia/tendenciasRESUMEN
The formation of reactive metabolites (RMs) is a problem in drug development that sometimes results in severe hepatotoxicity. As detecting RMs themselves is difficult, a covalent binding assay using expensive radiolabelled tracers is usually performed for candidate selection. This study aimed to provide a practical approach toward the risk assessment of hepatotoxicity induced by covalent binding before candidate selection. We focused on flutamide because it contains a trifluoromethyl group that shows a strong singlet peak by 19F nuclear magnetic resonance (NMR) spectrometry. The covalent binding of flutamide was evaluated using quantitative NMR and its risk for hepatotoxicity was assessed by estimating the RM burden, an index that reflects the body burden associated with RM exposure by determining the extent of covalent binding, clinical dose and in vivo clearance. The extent of covalent binding and RM burden was 296 pmol/mg/h and 37.9 mg/day, respectively. Flutamide was categorised as high risk with an RM burden >10 mg/day consistent with its clinical hepatotoxicity. These results indicate that a combination of covalent binding assay using 19F-NMR and RM burden is useful for the risk assessment of RMs without using radiolabelled compounds.
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Antineoplásicos Hormonales/toxicidad , Flutamida/toxicidad , Antineoplásicos Hormonales/metabolismo , Enfermedad Hepática Inducida por Sustancias y Drogas , Efectos Colaterales y Reacciones Adversas Relacionados con Medicamentos , Flutamida/metabolismo , Humanos , Espectroscopía de Resonancia Magnética , Microsomas Hepáticos/metabolismoRESUMEN
Hydrogenophilus thermoluteolus, Thermochromatium tepidum, and Allochromatium vinosum, which grow optimally at 52, 49, and 25 °C, respectively, have homologous cytochromes c' (PHCP, TTCP, and AVCP, respectively) exhibiting at least 50% amino acid sequence identity. Here, the thermal stability of the recombinant TTCP protein was first confirmed to be between those of PHCP and AVCP. Structure comparison of the 3 proteins and a mutagenesis study on TTCP revealed that hydrogen bonds and hydrophobic interactions between the heme and amino acid residues were responsible for their stability differences. In addition, PHCP, TTCP, and AVCP and their variants with altered stability similarly bound nitric oxide and carbon oxide, but not oxygen. Therefore, the thermal stability of TTCP together with PHCP and AVCP can be tuned through specific interactions around the heme without affecting their gas-binding function. These cytochromes c' will be useful as specific gas sensor proteins exhibiting a wide thermal stability range.
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Proteínas Bacterianas/metabolismo , Chromatiaceae/enzimología , Citocromos c'/metabolismo , Gases/metabolismo , Secuencia de Aminoácidos , Proteínas Bacterianas/química , Chromatiaceae/crecimiento & desarrollo , Dicroismo Circular , Cristalografía por Rayos X , Citocromos c'/química , Unión Proteica , Conformación Proteica , Desnaturalización Proteica , Proteínas Recombinantes/química , Proteínas Recombinantes/metabolismo , Homología de Secuencia de Aminoácido , TemperaturaRESUMEN
Hyperglycemia is an independent risk factor for diabetic heart failure. However, the mechanisms that mediate hyperglycemia-induced cardiac damage remain poorly understood. Previous studies have shown an association between lysosomal dysfunction and diabetic heart injury. The present study examined if mimicking hyperglycemia in cultured cardiomyocytes could induce lysosomal membrane permeabilization (LMP), leading to the release of lysosome enzymes and subsequent cell death. High glucose (HG) reduced the number of lysosomes with acidic pH as shown by a fluorescent pH indicator. Also, HG induced lysosomal membrane injury as shown by an accumulation of Galectin3-RFP puncta, which was accompanied by the leakage of cathepsin D (CTSD), an aspartic protease that normally resides within the lysosomal lumen. Furthermore, CTSD expression was increased in HG-cultured cardiomyocytes and in the hearts of 2 mouse models of type 1 diabetes. Either CTSD knockdown with siRNA or inhibition of CTSD activity by pepstatin A markedly diminished HG-induced cardiomyocyte death, while CTSD overexpression exaggerated HG-induced cell death. Together, these results suggested that HG increased CTSD expression, induced LMP and triggered CTSD release from the lysosomes, which collectively contributed to HG-induced cardiomyocyte injury.
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Catepsina D/metabolismo , Muerte Celular , Hiperglucemia/metabolismo , Hiperglucemia/patología , Lisosomas/metabolismo , Lisosomas/patología , Miocitos Cardíacos/metabolismo , Animales , Catepsina D/antagonistas & inhibidores , Catepsina D/genética , Células Cultivadas , Humanos , Concentración de Iones de Hidrógeno , Microscopía Fluorescente , Miocitos Cardíacos/patología , ARN Interferente Pequeño/farmacología , Ratas , Ratas Sprague-DawleyRESUMEN
INTRODUCTION: Diabetes mellitus is a serious metabolic disorder causing multiple organ damage in human. However, the lipidomic profiles in different organs and their associations are rarely studied in either diabetic patients or animals. OBJECTIVES: To evaluate and compare the characteristics of lipid species in serum and multiple tissues in a diabetic mouse model. METHODS: Semi-quantitative profiling analyses of intact and oxidized lipids were performed in serum and multiple tissues from a diabetic mouse model fed a high fat diet and treated with streptozotocin by using LC/HRMS and MS/MS. The total content of each lipid class, and the tissue-specific lipid species in all tissue samples were determined and compared by multivariate analyses. RESULTS: The diabetic mouse model displayed characteristic differences in serum and multiple organs: the brain and heart showed the largest reduction in cardiolipin, while the kidney had more alterations in triacylglycerol. Interestingly, the lipidomic differences also existed between different regions of the same organ: cardiolipin species with highly polyunsaturated fatty acyls decreased only in atrium but not in ventricle, while renal cortex showed longer fatty acyl chains for both increased and decreased triacylglycerol species than renal medulla. Importantly, diabetes caused an accumulation of lipid hydroperoxides, suggesting that oxidative stress was induced in all organs except for the brain during the development of diabetes. CONCLUSIONS: These findings provided novel insight into the organ-specific relationship between diabetes and lipid metabolism, which might be useful for evaluating not only diabetic tissue injury but also the effectiveness of diabetic treatments.
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Diabetes Mellitus Tipo 2/metabolismo , Metabolismo de los Lípidos , Lipidómica , Lípidos/sangre , Animales , Diabetes Mellitus Experimental/metabolismo , Peroxidación de Lípido , Lípidos/análisis , Ratones , Especificidad de Órganos , Estrés Oxidativo , Estreptozocina/toxicidad , Espectrometría de Masas en TándemRESUMEN
The protein kinase mechanistic target of rapamycin (mTOR) performs diverse cellular functions through 2 distinct multiprotein complexes, mTOR complex (mTORC)1 and 2. Numerous studies using rapamycin, an mTORC1 inhibitor, have implicated a role for mTORC1 in several types of heart disease. People with diabetes are more susceptible to heart failure. mTORC1 activity is increased in the diabetic heart, but its functional significance remains controversial. To investigate the role of mTORC1 in the diabetic heart, we crossed OVE26 type 1 diabetic mice with transgenic mice expressing a constitutively active mTOR (mTORca) or kinase-dead mTOR (mTORkd) in the heart. The expression of mTORca or mTORkd affected only mTORC1 but not mTORC2 activities, with corresponding changes in the activities of autophagy, a cellular degradation pathway negatively regulated by mTORC1. Diabetic cardiac damage in OVE26 mice was dramatically reduced by mTORca but exacerbated by mTORkd expression as assessed by changes in cardiac function, oxidative stress, and myocyte apoptosis. These findings demonstrated that the enhanced mTORC1 signaling in the OVE26 diabetic heart was an adaptive response that limited cardiac dysfunction, suggesting that manipulations that enhance mTORC1 activity may reduce diabetic cardiac injury, in sharp contrast to the results previously obtained with rapamycin.-Xu, X., Kobayashi, S., Timm, D., Huang, Y., Zhao, F., Shou, W., Liang, Q. Enhanced mTOR complex 1 signaling attenuates diabetic cardiac injury in OVE26 mice.
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Diabetes Mellitus Experimental/metabolismo , Diabetes Mellitus Tipo 1/metabolismo , Cardiomiopatías Diabéticas/metabolismo , Diana Mecanicista del Complejo 1 de la Rapamicina/metabolismo , Diana Mecanicista del Complejo 2 de la Rapamicina/metabolismo , Transducción de Señal , Animales , Diabetes Mellitus Experimental/genética , Diabetes Mellitus Experimental/patología , Diabetes Mellitus Tipo 1/genética , Diabetes Mellitus Tipo 1/patología , Cardiomiopatías Diabéticas/genética , Cardiomiopatías Diabéticas/patología , Diana Mecanicista del Complejo 1 de la Rapamicina/genética , Diana Mecanicista del Complejo 2 de la Rapamicina/genética , Ratones , Ratones TransgénicosRESUMEN
Doxorubicin (Dox) is a widely used antineoplastic agent that can cause heart failure. Dox cardiotoxicity is closely associated with mitochondrial damage. Mitochondrial fission and mitophagy are quality control mechanisms that normally help maintain a pool of healthy mitochondria. However, unchecked mitochondrial fission and mitophagy may compromise the viability of cardiomyocytes, predisposing them to cell death. Here, we tested this possibility by using Dox-treated H9c2 cardiac myoblast cells expressing either the mitochondria-targeted fluorescent protein MitoDsRed or the novel dual-fluorescent mitophagy reporter mt-Rosella. Dox induced mitochondrial fragmentation as shown by reduced form factor, aspect ratio, and mean mitochondrial size. This effect was abolished by short interference RNA-mediated knockdown of dynamin-related protein 1 (DRP1), a major regulator of fission. Importantly, DRP1 knockdown decreased cell death as indicated by the reduced number of propidium iodide-positive cells and the cleavage of caspase-3 and poly (ADP-ribose) polymerase. Moreover, DRP1-deficient mice were protected from Dox-induced cardiac damage, strongly supporting a role for DRP1-dependent mitochondrial fragmentation in Dox cardiotoxicity. In addition, Dox accelerated mitophagy flux, which was attenuated by DRP1 knockdown, as assessed by the mitophagy reporter mt-Rosella, suggesting the necessity of mitochondrial fragmentation in Dox-induced mitophagy. Knockdown of parkin, a positive regulator of mitophagy, dramatically diminished Dox-induced cell death, whereas overexpression of parkin had the opposite effect. Together, these results suggested that Dox cardiotoxicity was mediated, at least in part, by the increased mitochondrial fragmentation and accelerated mitochondrial degradation by the lysosome. Strategies that limit mitochondrial fission and mitophagy in the physiologic range may help reduce Dox cardiotoxicity.-Catanzaro, M. P., Weiner, A., Kaminaris, A., Li, C., Cai, F., Zhao, F., Kobayashi, S., Kobayashi, T., Huang, Y., Sesaki, H., Liang, Q. Doxorubicin-induced cardiomyocyte death is mediated by unchecked mitochondrial fission and mitophagy.
Asunto(s)
Cardiotoxicidad/etiología , Muerte Celular/efectos de los fármacos , Doxorrubicina/farmacología , Dinámicas Mitocondriales/efectos de los fármacos , Mitofagia/efectos de los fármacos , Miocitos Cardíacos/efectos de los fármacos , Animales , Cardiotoxicidad/metabolismo , Caspasa 3/metabolismo , Línea Celular , Dinaminas/metabolismo , Femenino , Humanos , Masculino , Ratones , Ratones Noqueados , Mitocondrias/efectos de los fármacos , Miocitos Cardíacos/metabolismo , ARN Interferente Pequeño/metabolismo , Ratas , Ubiquitina-Proteína Ligasas/metabolismoRESUMEN
BACKGROUND: Several inflammation-based scoring systems and nutritional indicators have been shown to have relevance to survival of patients with non-small cell lung cancer (NSCLC).The present study examined preoperative and pathological factors in patients who underwent curative resection for non-small cell lung cancer, with the aim to elucidate risk factors for early recurrence within 1 year of surgery. METHODS: Patients with NSCLC who underwent surgery from January 2009 to December 2014 were retrospectively investigated. Routine laboratory measurements including carcinoembryonic antigen were performed before surgery, and pathological information was collected after surgery. Patients with recurrence within 1 year after surgery were considered as early recurrence group (ERG), those with recurrence after 1 year were as late recurrence group (LRG), and those without recurrence were as no recurrence group (NRG). RESULTS: Multivariate analysis between ERG and LRG revealed Glasgow prognostic score (GPS) and CRP-to-albumin ratio (CAR) as independent risk factors for early recurrence. Multivariate analysis between ERG and LRG + NRG confirmed CAR, vascular invasion, and pathological stage as risk factors for early recurrence. CONCLUSION: These findings indicated that CAR and GPS were confirmed to be risk factors for early recurrence, in addition to pathological factors.
Asunto(s)
Carcinoma de Pulmón de Células no Pequeñas/cirugía , Inflamación/complicaciones , Neoplasias Pulmonares/cirugía , Recurrencia Local de Neoplasia/etiología , Adulto , Anciano , Anciano de 80 o más Años , Proteína C-Reactiva/análisis , Carcinoma de Pulmón de Células no Pequeñas/sangre , Carcinoma de Pulmón de Células no Pequeñas/patología , Femenino , Humanos , Neoplasias Pulmonares/sangre , Neoplasias Pulmonares/patología , Masculino , Persona de Mediana Edad , Estadificación de Neoplasias , Pronóstico , Estudios Retrospectivos , Factores de Riesgo , Albúmina Sérica/análisisRESUMEN
Many animals have an intrinsic growth checkpoint during juvenile development, after which an irreversible decision is made to upregulate steroidogenesis, triggering the metamorphic juvenile-to-adult transition. However, a molecular process underlying such a critical developmental decision remains obscure. Here we show that nutrient-dependent endocycling in steroidogenic cells provides the machinery necessary for irreversible activation of metamorphosis in Drosophila melanogaster. Endocycle progression in cells of the prothoracic gland (PG) is tightly coupled with the growth checkpoint, and block of endocycle in PG cells causes larval developmental arrest due to reduction in biosynthesis of the steroid hormone ecdysone. Moreover, inhibition of the nutrient sensor target of rapamycin (TOR) in the PG during the checkpoint period causes endocycle inhibition and developmental arrest, which can be rescued by inducing additional rounds of endocycles by Cyclin E. We propose that a TOR-mediated cell cycle checkpoint in steroidogenic tissue provides a systemic growth checkpoint for reproductive maturation.