RESUMEN

BACKGROUND: Dysregulated metabolism of bioactive sphingolipids, including ceramides and sphingosine-1-phosphate, has been implicated in cardiovascular disease, although the specific species, disease contexts, and cellular roles are not completely understood. Sphingolipids are produced by the serine palmitoyltransferase enzyme, canonically composed of 2 subunits, SPTLC1 (serine palmitoyltransferase long chain base subunit 1) and SPTLC2 (serine palmitoyltransferase long chain base subunit 2). Noncanonical sphingolipids are produced by a more recently described subunit, SPTLC3 (serine palmitoyltransferase long chain base subunit 3). METHODS: The noncanonical (d16) and canonical (d18) sphingolipidome profiles in cardiac tissues of patients with end-stage ischemic cardiomyopathy and in mice with ischemic cardiomyopathy were analyzed by targeted lipidomics. Regulation of SPTLC3 by HIF1α under ischemic conditions was determined with chromatin immunoprecipitation. Transcriptomics, lipidomics, metabolomics, echocardiography, mitochondrial electron transport chain, mitochondrial membrane fluidity, and mitochondrial membrane potential were assessed in the cSPTLC3KO transgenic mice we generated. Furthermore, morphological and functional studies were performed on cSPTLC3KO mice subjected to permanent nonreperfused myocardial infarction. RESULTS: Herein, we report that SPTLC3 is induced in both human and mouse models of ischemic cardiomyopathy and leads to production of atypical sphingolipids bearing 16-carbon sphingoid bases, resulting in broad changes in cell sphingolipid composition. This induction is in part attributable to transcriptional regulation by HIF1α under ischemic conditions. Furthermore, cardiomyocyte-specific depletion of SPTLC3 in mice attenuates oxidative stress, fibrosis, and hypertrophy in chronic ischemia, and mice demonstrate improved cardiac function and increased survival along with increased ketone and glucose substrate metabolism utilization. Depletion of SPTLC3 mechanistically alters the membrane environment and subunit composition of mitochondrial complex I of the electron transport chain, decreasing its activity. CONCLUSIONS: Our findings suggest a novel essential role for SPTLC3 in electron transport chain function and a contribution to ischemic injury by regulating complex I activity.

Asunto(s)

Cardiomiopatías , Complejo I de Transporte de Electrón , Serina C-Palmitoiltransferasa , Animales , Serina C-Palmitoiltransferasa/metabolismo , Serina C-Palmitoiltransferasa/genética , Ratones , Humanos , Cardiomiopatías/metabolismo , Cardiomiopatías/genética , Complejo I de Transporte de Electrón/metabolismo , Complejo I de Transporte de Electrón/genética , Esfingolípidos/metabolismo , Ratones Noqueados , Isquemia Miocárdica/metabolismo , Isquemia Miocárdica/genética , Isquemia Miocárdica/patología , Subunidad alfa del Factor 1 Inducible por Hipoxia/metabolismo , Subunidad alfa del Factor 1 Inducible por Hipoxia/genética , Masculino , Miocitos Cardíacos/metabolismo , Miocitos Cardíacos/patología

RESUMEN

The PTEN-induced kinase 1 (PINK1)-Parkin pathway plays a vital role in maintaining a healthy pool of mitochondria in higher eukaryotic cells. While the downstream components of this pathway are well understood, the upstream triggers remain less explored. In this study, we conducted an extensive analysis of inhibitors targeting various mitochondrial electron transport chain (ETC) complexes to investigate their potential as activators of the PINK1-Parkin pathway. We identified cloflucarban, an antibacterial compound, as a novel pathway activator that simultaneously inhibits mitochondrial complexes III and V, and V. RNA interference (RNAi) confirmed that the dual inhibition of these complexes activates the PINK1-Parkin pathway. Intriguingly, we discovered that albumin, specifically bovine serum albumin (BSA) and human serum albumin (HSA) commonly present in culture media, can hinder carbonyl cyanide m-chlorophenyl hydrazone (CCCP)-induced pathway activation. However, cloflucarban's efficacy remains unaffected by albumin, highlighting its reliability for studying the PINK1-Parkin pathway. This study provides insights into the activation of the upstream PINK1-Parkin pathway and underscores the influence of culture conditions on research outcomes. Cloflucarban emerges as a promising tool for investigating mitochondrial quality control and neurodegenerative diseases.

Asunto(s)

Carbanilidas , Proteínas Quinasas , Ubiquitina-Proteína Ligasas , Humanos , Proteínas Quinasas/metabolismo , Reproducibilidad de los Resultados , Ubiquitina-Proteína Ligasas/metabolismo , Mitocondrias/metabolismo , Albúminas/metabolismo

RESUMEN

Respiratory complex IV (CIV, cytochrome c oxidase) is the terminal enzyme of the mitochondrial electron transport chain. Some CIV subunits have two or more isoforms, which are ubiquitously expressed or are expressed in specific tissues like the lung, muscle, and testis. Among the tissue-specific CIV isoforms, the muscle-specific isoforms are expressed in adult cardiac and skeletal muscles. To date, the physiological and biochemical association between the muscle-specific CIV isoforms and aerobic respiration in muscles remains unclear. In this study, we profiled the CIV organization and expression pattern of muscle-specific CIV isoforms in different mouse muscle tissues. We found extensive CIV-containing supramolecular organization in murine musculature at advanced developmental stages, while a switch in the expression from ubiquitous to muscle-specific isoforms of CIV was also detected. Such a switch was confirmed during the in vitro differentiation of mouse C2C12 myoblasts. Unexpectedly, a CIV expression decrease was observed during C2C12 differentiation, which was probably due to a small increase in the expression of muscle-specific isoforms coupled with a dramatic decrease in the ubiquitous isoforms. We also found that the enzymatic activity of CIV containing the muscle-specific isoform COX6A2 was higher than that with COX6A1 in engineered HEK293T cells. Overall, our results indicate that switching the expression from ubiquitous to muscle-specific CIV isoforms is indispensable for optimized oxidative phosphorylation in mature skeletal muscles. We also note that the in vitro C2C12 differentiation model is not suitable for the study of muscular aerobic respiration due to insufficient expression of muscle-specific CIV isoforms.

Asunto(s)

Complejo IV de Transporte de Electrones , Músculo Esquelético , Masculino , Ratones , Animales , Humanos , Complejo IV de Transporte de Electrones/metabolismo , Células HEK293 , Músculo Esquelético/metabolismo , Mitocondrias/metabolismo , Isoformas de Proteínas/metabolismo

RESUMEN

The physiological role of mono-ADP-ribosyl transferase (Arr) of Mycobacterium smegmatis, which inactivates rifampicin, remains unclear. An earlier study reported increased expression of arr during oxidative stress and DNA damage. This suggested a role for Arr in the oxidative status of the cell and its associated effect on DNA damage. Since reactive oxygen species (ROS) influence oxidative status, we investigated whether Arr affected ROS levels in M. smegmatis. Significantly elevated levels of superoxide and hydroxyl radical were found in the mid-log phase (MLP) cultures of the arr knockout strain (arr-KO) as compared those in the wild-type strain (WT). Complementation of arr-KO with expression from genomically integrated arr under its native promoter restored the levels of ROS equivalent to that in WT. Due to the inherently high ROS levels in the actively growing arr-KO, rifampicin resisters with rpoB mutations could be selected at 0 hr of exposure itself against rifampicin, unlike in the WT where the resisters emerged at 12th hr of rifampicin exposure. Microarray analysis of the actively growing cultures of arr-KO revealed significantly high levels of expression of genes from succinate dehydrogenase I and NADH dehydrogenase I operons, which would have contributed to the increased superoxide levels. In parallel, expression of specific DNA repair genes was significantly decreased, favouring retention of the mutations inflicted by the ROS. Expression of several metabolic pathway genes also was significantly altered. These observations revealed that Arr was required for maintaining a gene expression profile that would provide optimum levels of ROS and DNA repair system in the actively growing M. smegmatis.

RESUMEN

Aging impairs mitochondrial function that leads to greater cardiac injury during ischemia and reperfusion. Cardiac endoplasm reticulum (ER) stress increases with age and contributes to mitochondrial dysfunction. Metformin is an anti-diabetic drug that protects cardiac mitochondria during acute ER stress. We hypothesized that metformin treatment would improve preexisting mitochondrial dysfunction in aged hearts by attenuating ER stress, followed by a decrease in cardiac injury during subsequent ischemia and reperfusion. Male young (3 mo.) and aged mice (24 mo.) received metformin (300 mg/kg/day) dissolved in drinking water with sucrose (0.2 g/100 ml) as sweetener for two weeks versus sucrose vehicle alone. Cytosol, subsarcolemmal (SSM), and interfibrillar mitochondria (IFM) were isolated. In separate groups, cardioprotection was evaluated using ex vivo isolated heart perfusion with 25 min. global ischemia and 60 min. reperfusion. Infarct size was measured. The contents of CHOP and cleaved ATF6 were decreased in metformin-treated 24 mo. mice compared to vehicle, supporting a decrease in ER stress. Metformin treatment improved OXPHOS in IFM in 24 mo. using a complex I substrate. Metformin treatment decreased infarct size following ischemia-reperfusion. Thus, metformin feeding decreased cardiac injury in aged mice during ischemia-reperfusion by improving pre-ischemic mitochondrial function via inhibition of ER stress.

Asunto(s)

Estrés del Retículo Endoplásmico/efectos de los fármacos , Metformina/farmacología , Mitocondrias Cardíacas/efectos de los fármacos , Daño por Reperfusión Miocárdica/prevención & control , Sustancias Protectoras/farmacología , Factores de Edad , Animales , Complejo I de Transporte de Electrón/metabolismo , Masculino , Metformina/uso terapéutico , Ratones , Mitocondrias Cardíacas/metabolismo , Reperfusión Miocárdica , Daño por Reperfusión Miocárdica/metabolismo , Fosforilación/efectos de los fármacos , Piperazinas/metabolismo , Sustancias Protectoras/uso terapéutico , Compuestos de Amonio Cuaternario/metabolismo , Serina-Treonina Quinasas TOR/metabolismo , Factor de Transcripción CHOP/metabolismo

RESUMEN

OBJECTIVE: The present study was designed to test the hypothesis that there is a reduction in the activity of the enzyme cytochrome c oxidase (Cox) in Alzheimer's disease (AD). METHODS: Systematic review of literature and meta-analysis were used with data obtained from the PubMed, Scopus, MEDLINE, Lilacs, Eric and Cochrane. The keywords were Alzheimer's AND Cox AND mitochondria; Alzheimer's AND Cox AND mitochondria; Alzheimer's AND complex IV AND mitochondria. A total of 1372 articles were found, 23 of them fitting the inclusion criteria. The data were assembled in an Excel spreadsheet and analysed using the RevMan software. A random effects model was adopted to the estimative of the effect. RESULTS: The data shows a significant decrease in the activity of the Cox AD patients and animal models. CONCLUSION: Cox enzyme may be an important molecular component involved in the mechanisms underlying AD. Therefore, this enzyme may represent a possible new biomarker for the disease as a complementary diagnosis and a new treatment target for AD.

Asunto(s)

Enfermedad de Alzheimer/enzimología , Complejo IV de Transporte de Electrones/metabolismo , Mitocondrias/enzimología , Enfermedad de Alzheimer/diagnóstico , Animales , Colorimetría/métodos , Humanos , Ratones , Mitocondrias/metabolismo , Modelos Animales , Polarografía/métodos , Ratas , Programas Informáticos , Espectrofotometría/métodos

RESUMEN

Diabetic nephropathy (DN) has become the main cause of end-stage renal disease worldwide, but the efficacy of current therapeutic strategies on DN remains unsatisfactory. Recent research has reported the involvement of metabolic rearrangement in the pathological process of DN, and of all the disturbances in metabolism, mitochondria serve as key regulatory hubs. In the present study, high-resolution mass spectrometry-based nontarget metabolomics was used to uncover the metabolic characteristics of the early diabetic kidney with or without the inhibition of mitochondrial activity. At first, we observed a moderate enhancement of mitochondrial complex-1 activity in the diabetic kidney, which was completely normalized by the specific mitochondrial complex-1 inhibitor rotenone (ROT). Meanwhile, metabolomics data indicated an overactivated pentose phosphate pathway, purine and pyrimidine metabolism, hexosamine biosynthetic pathway, and tricarboxylic acid cycle, which were strikingly corrected by ROT. In addition, ROT also strikingly corrected imbalanced redox homeostasis, possibly by increasing the ratio of antioxidant metabolites glutathione and NADPH against their oxidative form. In agreement with the improved metabolic status and oxidative response, ROT attenuated glomerular and tubular injury efficiently. Fibrotic markers (fibronectin, α-smooth muscle actin, collagen type I, and collagen type III), inflammatory factors (TNF-α, IL-1ß, and ICAM-1), and oxidative stress were all markedly blocked by ROT. In vitro, ROT dose dependently attenuated high glucose-induced proliferation and extracellular matrix production in mesangial cells. Collectively, these findings revealed that the overactivation of mitochondrial activity in the kidney could contribute to metabolic disorders and the pathogenesis of early DN.

Asunto(s)

Diabetes Mellitus Experimental/complicaciones , Nefropatías Diabéticas/etiología , Metabolismo Energético , Riñón/metabolismo , Mitocondrias/metabolismo , Animales , Glucemia/metabolismo , Línea Celular , Proliferación Celular , Cromatografía Líquida de Alta Presión , Diabetes Mellitus Experimental/inducido químicamente , Diabetes Mellitus Experimental/metabolismo , Nefropatías Diabéticas/tratamiento farmacológico , Nefropatías Diabéticas/metabolismo , Nefropatías Diabéticas/patología , Complejo I de Transporte de Electrón/antagonistas & inhibidores , Complejo I de Transporte de Electrón/metabolismo , Metabolismo Energético/efectos de los fármacos , Fibrosis , Homeostasis , Mediadores de Inflamación/metabolismo , Riñón/efectos de los fármacos , Riñón/patología , Masculino , Metabolómica/métodos , Ratones Endogámicos C57BL , Mitocondrias/efectos de los fármacos , Mitocondrias/patología , Nefrectomía , Estrés Oxidativo , Rotenona/farmacología , Espectrometría de Masa por Ionización de Electrospray , Estreptozocina , Espectrometría de Masas en Tándem , Desacopladores/farmacología

RESUMEN

To report a case of imported furuncular cutaneous myiasis,and to analyze the sequence of the mitochondrial cytochrome C oxidase subunit Ⅰ (CO Ⅰ) gene of the pathogenic Cordylobia anthropophaga.A 33-year-old female patient had a travel history to Ghana and Cameroon in Africa 1 month prior to the presentation.No anti-mosquito measures were taken during her stay,and she hung up the laundries outside to dry for several times.Skin examination showed furuncular protuberances with diameters of 1-2 cm on the inner side of the left upper arm as well as on the outer side of the left chest,which were bright red and hard on palpation with irregular borders and a small hole on their central surface.Morphological identification revealed that the larva squeezed from the lesion was suspected as myiasis.After PCR amplification of the CO Ⅰ gene of the larva,an about 650-bp PCR product was acquired.Sequencing and BLAST analysis showed that this product was most closely related to the CO Ⅰ gene (GenBank accession number:FR719158.1) of Cordylobia anthropophaga isolated in Cameroon in 2010 with the sequence similarity being 99.84％,and they were grouped together on the phylogenetic tree.According to the clinical features and travel history of the patient and the sequencing results of the pathogenic Cordylobia anthropophaga,this case was confirmed as imported furuncular cutaneous myiasis caused by Cordylobia anthropophaga.

RESUMEN

Alzheimer's disease (AD) is a severe neurodegenerative disorder for which the exact etiology is largely unknown. An increasingly recognized and investigated notion is the pathogenic role of mitochondrial dysfunction in AD. We assessed mitochondrial oxidative-phosphorylation (OXPHOS) enzyme activities in the APPswe/PS1ΔE9 mouse model from 4.5 to 14 months of age. We show an age-dependent decrease in mitochondrial complex-II activity starting at 9 months in APP/PS1 mice. Other enzymes of the OXPHOS do not show any alterations. Since amyloid-ß (Aß) plaques are already present from 4 months of age, mitochondrial dysfunction likely occurs downstream of Aß pathology in this mouse model.

Asunto(s)

Enfermedad de Alzheimer/genética , Enfermedad de Alzheimer/metabolismo , Modelos Animales de Enfermedad , Complejo IV de Transporte de Electrones/genética , Complejo IV de Transporte de Electrones/metabolismo , Fosforilación Oxidativa , Factores de Edad , Enfermedad de Alzheimer/patología , Animales , Masculino , Ratones , Ratones Endogámicos C3H , Ratones Endogámicos C57BL , Ratones Transgénicos

RESUMEN

Recent advances in our understanding of tumor cell mitochondrial metabolism suggest it may be an attractive therapeutic target. Mitochondria are central hubs of metabolism that provide energy during the differentiation and maintenance of immune cell phenotypes. Mitochondrial membranes harbor several enzyme complexes that are involved in the process of oxidative phosphorylation, which takes place during energy production. Data suggest that, among these enzyme complexes, deficiencies in electron transport complex I may differentially affect immune responses and may contribute to the pathophysiology of several immunological conditions. Once activated by T cell receptor signaling, along with co-stimulation through CD28, CD4 T cells utilize mitochondrial energy to differentiate into distinct T helper (Th) subsets. T cell signaling activates Notch1, which is cleaved from the plasma membrane to generate its intracellular form (N1ICD). In the presence of specific cytokines, Notch1 regulates gene transcription related to cell fate to modulate CD4 Th type 1, Th2, Th17, and induced regulatory T cell (iTreg) differentiation. The process of differentiating into any of these subsets requires metabolic energy, provided by the mitochondria. We hypothesized that the requirement for mitochondrial metabolism varies between different Th subsets and may intersect with Notch1 signaling. We used the organic pesticide rotenone, a well-described complex I inhibitor, to assess how compromised mitochondrial integrity impacts CD4 T cell differentiation into Th1, Th2, Th17, and iTreg cells. We also investigated how Notch1 localization and downstream transcriptional capabilities regulation may be altered in each subset following rotenone treatment. Our data suggest that mitochondrial integrity impacts each of these Th subsets differently, through its influence on Notch1 subcellular localization. Our work further supports the notion that altered immune responses can result from complex I inhibition. Therefore, understanding how mitochondrial inhibitors affect immune responses may help to inform therapeutic approaches to cancer treatment.

Asunto(s)

Diferenciación Celular/efectos de los fármacos , Diferenciación Celular/inmunología , Complejo I de Transporte de Electrón/metabolismo , Rotenona/farmacología , Linfocitos T Colaboradores-Inductores/efectos de los fármacos , Linfocitos T Colaboradores-Inductores/fisiología , Factores de Transcripción/metabolismo , Animales , Biomarcadores , Regulación de la Expresión Génica/efectos de los fármacos , Inmunofenotipificación , Espacio Intracelular/metabolismo , Activación de Linfocitos/efectos de los fármacos , Activación de Linfocitos/genética , Activación de Linfocitos/inmunología , Ratones , Mitocondrias/efectos de los fármacos , Mitocondrias/inmunología , Mitocondrias/metabolismo , Miembro 3 del Grupo F de la Subfamilia 1 de Receptores Nucleares/metabolismo , Transporte de Proteínas , Subgrupos de Linfocitos T/citología , Subgrupos de Linfocitos T/efectos de los fármacos , Subgrupos de Linfocitos T/inmunología , Subgrupos de Linfocitos T/metabolismo , Linfocitos T Colaboradores-Inductores/citología , Factores de Transcripción/genética

RESUMEN

RATIONALE: Acute pulmonary oxygen sensing is essential to avoid life-threatening hypoxemia via hypoxic pulmonary vasoconstriction (HPV) which matches perfusion to ventilation. Hypoxia-induced mitochondrial superoxide release has been suggested as a critical step in the signaling pathway underlying HPV. However, the identity of the primary oxygen sensor and the mechanism of superoxide release in acute hypoxia, as well as its relevance for chronic pulmonary oxygen sensing, remain unresolved. OBJECTIVES: To investigate the role of the pulmonary-specific isoform 2 of subunit 4 of the mitochondrial complex IV (Cox4i2) and the subsequent mediators superoxide and hydrogen peroxide for pulmonary oxygen sensing and signaling. METHODS AND RESULTS: Isolated ventilated and perfused lungs from Cox4i2-/- mice lacked acute HPV. In parallel, pulmonary arterial smooth muscle cells (PASMCs) from Cox4i2-/- mice showed no hypoxia-induced increase of intracellular calcium. Hypoxia-induced superoxide release which was detected by electron spin resonance spectroscopy in wild-type PASMCs was absent in Cox4i2-/- PASMCs and was dependent on cysteine residues of Cox4i2. HPV could be inhibited by mitochondrial superoxide inhibitors proving the functional relevance of superoxide release for HPV. Mitochondrial hyperpolarization, which can promote mitochondrial superoxide release, was detected during acute hypoxia in wild-type but not Cox4i2-/- PASMCs. Downstream signaling determined by patch-clamp measurements showed decreased hypoxia-induced cellular membrane depolarization in Cox4i2-/- PASMCs compared with wild-type PASMCs, which could be normalized by the application of hydrogen peroxide. In contrast, chronic hypoxia-induced pulmonary hypertension and pulmonary vascular remodeling were not or only slightly affected by Cox4i2 deficiency, respectively. CONCLUSIONS: Cox4i2 is essential for acute but not chronic pulmonary oxygen sensing by triggering mitochondrial hyperpolarization and release of mitochondrial superoxide which, after conversion to hydrogen peroxide, contributes to cellular membrane depolarization and HPV. These findings provide a new model for oxygen-sensing processes in the lung and possibly also in other organs.

Asunto(s)

Complejo IV de Transporte de Electrones/metabolismo , Pulmón/metabolismo , Mitocondrias/metabolismo , Oxígeno/metabolismo , Animales , Hipoxia de la Célula/fisiología , Línea Celular Tumoral , Complejo IV de Transporte de Electrones/genética , Femenino , Humanos , Masculino , Potencial de la Membrana Mitocondrial/fisiología , Ratones , Ratones Noqueados , Mitocondrias/genética

RESUMEN

Leigh disease is a progressive, infantile-onset, neurodegenerative disorder characterized by feeding difficulties, failure to thrive, hypotonia, seizures, and central respiratory compromise. Metabolic and neuroimaging investigations typically identify abnormalities consistent with a disorder of mitochondrial energy metabolism. Mutations in more than 35 genes affecting the mitochondrial respiratory chain encoded from both the nuclear and mitochondrial genomes have been associated with Leigh disease. The clinical presentations of five individuals of Hutterite descent with Leigh disease are described herein. An identity-by-descent mapping and candidate gene approach was used to identify a novel homozygous c.393dupA frameshift mutation in the NADH dehydrogenase (ubiquinone) Fe-S protein 4 (NDUFS4) gene. The carrier frequency of this mutation was estimated in >1,300 Hutterite individuals to be 1 in 27. © 2017 Wiley Periodicals, Inc.

Asunto(s)

Etnicidad/genética , Mutación del Sistema de Lectura , Estudios de Asociación Genética , Enfermedad de Leigh/diagnóstico , Enfermedad de Leigh/genética , NADH Deshidrogenasa/genética , Fenotipo , Canadá , Consanguinidad , Análisis Mutacional de ADN , Complejo I de Transporte de Electrón , Femenino , Genotipo , Humanos , Lactante , Imagen por Resonancia Magnética , Masculino , Análisis de Secuencia por Matrices de Oligonucleótidos , Linaje , Polimorfismo de Nucleótido Simple , Hermanos , Estados Unidos

RESUMEN

STUDY QUESTION: Does supplementation with co-enzyme Q10 (CoQ10) improve the oocyte mitochondrial abnormalities associated with obesity in mice? SUMMARY ANSWER: In an obese mouse model, CoQ10 improves the mitochondrial function of oocytes. WHAT IS KNOWN ALREADY: Obesity impairs oocyte quality. Oocytes from mice fed a high-fat/high-sugar (HF/HS) diet have abnormalities in mitochondrial distribution and function and in meiotic progression. STUDY DESIGN, SIZE, DURATION: Mice were randomly assigned to a normal, chow diet or an isocaloric HF/HS diet for 12 weeks. After 6 weeks on the diet, half of the mice receiving a normal diet and half of the mice receiving a HF/HS diet were randomly assigned to receive CoQ10 supplementation injections for the remaining 6 weeks. PARTICIPANTS/MATERIALS, SETTING, METHODS: Dietary intervention was initiated on C57Bl6 female mice at 4 weeks of age, CoQ10 versus vehicle injections were assigned at 10 weeks, and assays were conducted at 16 weeks of age. Mice were super-ovulated, and oocytes were collected and stained to assess mitochondrial distribution, quantify reactive oxygen species (ROS), assess meiotic spindle formation, and measure metabolites. In vitro fertilization was performed, and blastocyst embryos were transferred into control mice. Oocyte number, fertilization rate, blastulation rate and implantation rate were compared between the four cohorts. Bivariate statistics were performed appropriately. MAIN RESULTS AND THE ROLE OF CHANCE: HF/HS mice weighed significantly more than normal diet mice (29 versus 22 g, P< 0.001). CoQ10 supplementation did not influence weight. Levels of ATP, citrate, and phosphocreatine were lower and ROS levels were higher in HF/HS mice than in controls (P< 0.001). CoQ10 supplementation significantly increased the levels of metabolites and decreased ROS levels in oocytes from normal diet mice but not in oocytes from HF/HS mice. However, CoQ10 completely prevented the mitochondrial distribution abnormalities observed in the HF/HS mice. Overall, CoQ10 supplementation significantly increased the percentage of normal spindle and chromosome alignment (92.3 versus 80.2%, P= 0.039). In the sub-analysis by diet, the difference did not reach statistical significance. When undergoing IVF, there were no statistically significant differences in the number of mature oocytes, the fertilization rate, blastocyst formation rates, implantation rates, resorption rates or litter size between HF/HS mice receiving CoQ10 or vehicle injections. LIMITATIONS, REASONS FOR CAUTION: Experiments were limited to one species and strain of mice. The majority of experiments were performed after ovulation induction, which may not represent natural cycle fertility. WIDER IMPLICATIONS OF THE FINDINGS: Improvement in oocyte mitochondrial distribution and function of normal, chow-fed mice and HF/HS-fed mice demonstrates the importance of CoQ10 and the efficiency of the mitochondrial respiratory chain in oocyte competence. Clinical studies are now needed to evaluate the therapeutic potential of CoQ10 in women's reproductive health. STUDY FUNDING/COMPETING INTERESTS: C.E.B. received support from the National Research Training Program in Reproductive Medicine sponsored by the National Institute of Health (T32 HD040135-13) and the Scientific Advisory Board of Vivere Health. K.H.M received support from the American Diabetes Association and the National Institute of Health (R01 HD083895). There are no conflicts of interest to declare. TRIAL REGISTRATION NUMBER: This study is not a clinical trial.

Asunto(s)

Mitocondrias/efectos de los fármacos , Obesidad/metabolismo , Oocitos/efectos de los fármacos , Ubiquinona/análogos & derivados , Animales , Peso Corporal/efectos de los fármacos , Peso Corporal/fisiología , Dieta Alta en Grasa , Modelos Animales de Enfermedad , Femenino , Ratones , Mitocondrias/metabolismo , Oocitos/metabolismo , Especies Reactivas de Oxígeno/metabolismo , Resultado del Tratamiento , Ubiquinona/farmacología

RESUMEN

Growing evidence suggests that mitochondrial reactive oxygen species (ROS) are involved in various pain states. This study was performed to investigate whether ROS-induced changes in neuronal excitability in trigeminal subnucleus caudalis are related to ROS generation in mitochondria. Confocal scanning laser microscopy was used to measure ROS-induced fluorescence intensity in live rat trigeminal caudalis slices. The ROS level increased during the perfusion of malate, a mitochondrial substrate, after loading of 2',7'-dichlorofluorescin diacetate (H2DCF-DA), an indicator of the intracellular ROS; the ROS level recovered to the control condition after washout. When pre-treated with phenyl N-tert-butylnitrone (PBN) and 4-hydroxy-2,2,6,6-tetramethylpiperidene-1-oxyl (TEMPOL), malate-induced increase of ROS level was suppressed. To identify the direct relation between elevated ROS levels and mitochondria, we applied the malate after double-loading of H2DCF-DA and chloromethyl-X-rosamine (CMXRos; MitoTracker Red), which is a mitochondria-specific fluorescent probe. As a result, increase of both intracellular ROS and mitochondrial ROS were observed simultaneously. This study demonstrated that elevated ROS in trigeminal subnucleus caudalis neuron can be induced through mitochondrial-ROS pathway, primarily by the leakage of ROS from the mitochondrial electron transport chain.

Asunto(s)

Animales , Ratas , Transporte de Electrón , Fluorescencia , Microscopía Confocal , Mitocondrias , Neuronas , Perfusión , Especies Reactivas de Oxígeno

RESUMEN

Objective: To observe the effect of electroacupuncture (EA) on cytochrome c oxidase (COX)activity of hippocampal mitochondria in senescence-accelerated mouse prone 8 (SAMP8) mice, and to explore the EA mechanism on Alzheimer disease (AD) in improving energy metabolic disorder. Methods: Twelve SAMP8 mice were randomly divided into a model group and an EA group, with six in each group. Six senescence-accelerated mouse resistance 1 (SAMR1) mice were prepared as blank group. Mice in the EA group received EA on Baihui (GV 20) and Yongquan (KI 1), once a day for 7 d as a course, altogether 3 courses with one day intervalbetween two courses. Mice in the model group and the blank group were manipulated and fixed as those in the EA group. After interventions, Morris water maze was employed to test spatial learning and memory ability to evaluate EA effect; spectrophotometry was used to detect the activity of hippocampal mitochondria COX. Results: Compared with the blank group, mean escape latenciesof the EA group and model group were prolonged significantly in Morris water maze tests (P Conclusion: It’s plausible that EA improves AD learning and memory ability by increasing mitochondria COX activity, protecting the structure and function, and improving energy metabolism.

RESUMEN

Objective To construct the recombinant adenovirus vector containing ubiquinol-cytochrome C reductase core protein 1(UQCRC1) and to investigate the protective role of UQCRC1 against hypoxia/reoxygenation injury in H9c2 cardiac myocytes . Methods UQCRC1 gene was obtained from the cDNA library by PCR ,then was double-digested with restriction endonucleases SalⅠand XbaⅠand inserted into pAd Track-CMV .The identified plasmid of pAd Track-UQCRC1 was transfected into BJ 5183 contai-ning pAdEasy-1 .After screening the positive clone ,the plasmid was transfect into 293T cells with liposome to integrate and package the recombinant adenovirus .Finally ,these adenoviruses were transfected into H9c2 cardiac myocytes .The expressions of green fluo-rescence protein(GFP) ,UQCRC1 gene and protein were observed by RT-PCR and Western blot analysis .The cell viability and the LDH release were detect .Results The recombinant adenovirus-UQCRC1 was constructed successfully .The overexpression of UQCRC1 increased the cell viability(P<0 .05) and decreased the LDH release(P<0 .05) from H9C2 cardiac myocytes after suf-fering hypoxia/reoxygenation injury .Conclusion UQCRC1 has the protective effect on hypoxia/reoxygenation injury in H9c2 car-diac myocytes ,and the construction of recombinant adenovirus vector will lay the foundation for further studying the role of UQCRC1 in cardioprotection .

RESUMEN

BACKGROUND:How to control functional activity of donor liver after cardiac death and maintain the optimal function of grafts are the key issues in organ transplantation study. OBJECTIVE:To preliminarily explore the effect of warm ischemia injury on the morphology and function of rat donor liver after cardiac death. METHODS:Cardiac death model was established in Sprague-Dawley rats and the successful models were divided into six groups:control group (warm ischemia for 0 minute), warm ischemia 10 group (warm ischemia for 10 minutes), warm ischemia 20 group (warm ischemia for 20 minutes), warm ischemia 30 group (warm ischemia for 30 minutes), warm ischemia 40 group (warm ischemia for 40 minutes) and warm ischemia 50 group (warm ischemia for 50 minutes). The rat liver specimens in each group were cut into ultrathin sections. The structure of liver cells was observed and photographed by electron microscopy. Flameng score was applied to analyze the degree of mitochondrial damage. Liver mitochondria were extracted and then spectrophotometry was used to assess the viability of cytochrome C oxidase. RESULTS AND CONCLUSION:Under electron microscopy, there were no significant changes in liver cells within 30 minutes of warm ischemia, nuclear membrane was intact, mitochondria mildly swel ed, no mitochondrial crista ruptured, and Flameng score was<2 points. With the extension of warm ischemia time, the cells became swel ing, nuclear chromatin condensated, apoptotic body was clearly visible, mitochondrial matrix coagulated, mitochondria exhibited vacuolation, and Flameng score was 3-4 points. The viability of cytochrome C oxidase showed no significant difference within 30 minutes of warm ischemia, but began to significantly decrease at 40 and 50 minutes. The mitochondrial structure and function after liver injury is not obviously affected by 30 minutes of warm ischemia, and significant changes appear after 40 minutes.

RESUMEN

Mitochondrial dysfunction is associated with various forms of lung injury and disease that also involve alterations in pulmonary endothelial permeability, but the relationship, if any, between the two is not well understood. This question was addressed by perfusing isolated intact rat lung with a buffered physiological saline solution in the absence or presence of the mitochondrial complex I inhibitor rotenone (20 µM). Compared to control, rotenone depressed whole lung tissue ATP from 5.66 ± 0.46 (SEM) to 2.34 ± 0.15 µmol · g(-1) dry lung, with concomitant increases in the ADP:ATP and AMP:ATP ratios. Rotenone also increased lung perfusate lactate (from 12.36 ± 1.64 to 38.62 ± 3.14 µmol · 15 min(-1) perfusion · g(-1) dry lung) and the lactate:pyruvate ratio, but had no detectable impact on lung tissue GSH:GSSG redox status. The amphipathic quinone coenzyme Q1 (CoQ1; 50 µM) mitigated the impact of rotenone on the adenine nucleotide balance, wherein mitigation was blocked by NAD(P)H-quinone oxidoreductase 1 or mitochondrial complex III inhibitors. In separate studies, rotenone increased the pulmonary vascular endothelial filtration coefficient (Kf) from 0.043 ± 0.010 to 0.156 ± 0.037 ml · min(-1) · cm H2O(-1) · g(-1) dry lung, and CoQ1 protected against the effect of rotenone on Kf. A second complex I inhibitor, piericidin A, qualitatively reproduced the impact of rotenone on Kf and the lactate:pyruvate ratio. Taken together, the observations imply that pulmonary endothelial barrier integrity depends on mitochondrial bioenergetics as reflected in lung tissue ATP levels and that compensatory activation of whole lung glycolysis cannot protect against pulmonary endothelial hyperpermeability in response to mitochondrial blockade. The study further suggests that low-molecular-weight amphipathic quinones may have therapeutic utility in protecting lung barrier function in mitochondrial insufficiency.

Asunto(s)

Complejo I de Transporte de Electrón/antagonistas & inhibidores , Pulmón/irrigación sanguínea , Mitocondrias/metabolismo , Rotenona/farmacología , Ubiquinona/farmacología , Adenosina Trifosfato/análisis , Animales , Antibacterianos/farmacología , Barrera Alveolocapilar/efectos de los fármacos , Permeabilidad Capilar , Complejo III de Transporte de Electrones/antagonistas & inhibidores , Endotelio Vascular/metabolismo , Metabolismo Energético , Glucólisis , Ácido Láctico/análisis , Lesión Pulmonar , Masculino , NAD(P)H Deshidrogenasa (Quinona)/farmacología , Oxidación-Reducción/efectos de los fármacos , Piridinas/farmacología , Ácido Pirúvico/análisis , Ratas , Ratas Sprague-Dawley , Reperfusión , Desacopladores/farmacología

RESUMEN

Objective To investigate the neuroprotective effect of miR-181c on hypoxia-preconditioned ischemia in rats and its mechanism.Methods Thirty-nine male SD rats were randomly divided into 5 groups of control group,sham-operated group,middle cerebral artery occlusion (MCAO)group,hypoxia-preconditioned group,hypoxia-preconditioned and MCAO group.Infarct volume and behavioral deficits were quantified.Real-time PCR was applied to detect the expression levels of miR-181c and Western blotting was used to verify the target protein of mt-cox1.Results Under the treatment of hypoxia-preconditioned,the neurological impairment was alleviated and the infarct volume was reduced significantly from 22.50％ ±2.96％ to 16.40％ ±3.13 ％ (t =5.26,P ＜0.01).The expression of miR-181c was decreased significantly in hypoxia-preconditioned and MCAO group than that in MCAO group (1.89 ± 0.14 vs 3.05 ± 0.26,t =6.10,P ＜ 0.01),and the expression of mt-cox1 protein was also significantly decreased (0.54 ± 0.07 vs 0.93 ± 0.04,t =8.01,P ＜ 0.01).Conclusion Hypoxia-preconditioned may attenuate the ischemic injury in SD rats,which may be related to the down-regulation of the expression of miR-181c,therefore increasing the expression of its targeted protein mt-cox1.

RESUMEN

Mycothiazole, a polyketide metabolite isolated from the marine sponge Cacospongia mycofijiensis, is a potent inhibitor of metabolic activity and mitochondrial electron transport chain complex I in sensitive cells, but other cells are relatively insensitive to the drug. Sensitive cell lines (IC(50) 0.36-13.8 nM) include HeLa, P815, RAW 264.7, MDCK, HeLa S3, 143B, 4T1, B16, and CD4/CD8 T cells. Insensitive cell lines (IC(50) 12.2-26.5 µM) include HL-60, LN18, and Jurkat. Thus, there is a 34,000-fold difference in sensitivity between HeLa and HL-60 cells. Some sensitive cell lines show a biphasic response, suggesting more than one mechanism of action. Mitochondrial genome-knockout ρ(0) cell lines are insensitive to mycothiazole, supporting a conditional mitochondrial site of action. Mycothiazole is cytostatic rather than cytotoxic in sensitive cells, has a long lag period of about 12 h, and unlike the complex I inhibitor, rotenone, does not cause G(2)/M cell cycle arrest. Mycothiazole decreases, rather than increases the levels of reactive oxygen species after 24 h. It is concluded that the cytostatic inhibitory effects of mycothiazole on mitochondrial electron transport function in sensitive cell lines may depend on a pre-activation step that is absent in insensitive cell lines with intact mitochondria, and that a second lower-affinity cytotoxic target may also be involved in the metabolic and growth inhibition of cells.

Asunto(s)

Complejo I de Transporte de Electrón/antagonistas & inhibidores , Genoma Mitocondrial , Mitocondrias/efectos de los fármacos , Mitocondrias/metabolismo , Tiazoles/farmacología , Animales , Organismos Acuáticos/química , Organismos Acuáticos/metabolismo , Ciclo Celular/efectos de los fármacos , Línea Celular , Línea Celular Tumoral , Proliferación Celular/efectos de los fármacos , Supervivencia Celular/efectos de los fármacos , Perros , Células HL-60 , Células HeLa , Humanos , Células Jurkat , Ratones , Mitocondrias/genética , Poríferos/química , Poríferos/metabolismo , Especies Reactivas de Oxígeno/metabolismo