Progress in the regulation of energy metabolic homeostasis by the SWI/SNF complex subunit Baf60a / 生物工程学报

Metabolic syndrome is a global chronic epidemic. Its pathogenesis is determined by genetic and environmental factors. Epigenetic modification is reported to regulate gene expression without altering its nucleotide sequences. In recent years, epigenetic modification is sensitively responded to environmental signals, further affecting the gene expression and signaling transduction. Among these regulators, chromatin remodeling SWI/SNF (SWItch/Sucrose non fermentable, SWI/SNF) complex subunit Baf60a plays an important role in maintaining energy homeostasis in mammals. In this paper, we described the pathophysiological roles of Baf60a in maintaining the balance of energy metabolism, including lipid metabolism, cholesterol metabolism, urea metabolism, as well as their rhythmicity. Therefore, in-depth understanding of Baf60a-orchestrated transcriptional network of energy metabolism will provide potential therapeutic targets and reliable theoretical supports for the treatment of metabolic syndrome.

Androgen receptor deficiency in monocytes/macrophages does not alter adiposity or glucose homeostasis in male mice / 亚洲男科学杂志(英文版)

Androgen deprivation in men leads to increased adiposity, but the mechanisms underlying androgen regulation of fat mass have not been fully defined. Androgen receptor (AR) is expressed in monocytes/macrophages, which are resident in key metabolic tissues and influence energy metabolism in surrounding cells. Male mice bearing a cell-specific knockout of the AR in monocytes/macrophages (M-ARKO) were generated to determine whether selective loss of androgen signaling in these cells would lead to altered body composition. Wild-type (WT) and M-ARKO mice (12-22 weeks of age, n = 12 per group) were maintained on a regular chow diet for 8 weeks and then switched to a high-fat diet for 8 additional weeks. At baseline and on both the regular chow and high-fat diets, no differences in lean mass or fat mass were observed between groups. Consistent with the absence of differential body weight or adiposity, no differences in food intake (3.0 ± 0.5 g per day for WT mice vs 2.8 ± 0.4 g per day for M-ARKO mice) or total energy expenditure (0.6 ± 0.1 Kcal h-1 for WT mice vs 0.5 ± 0.1 Kcal h-1 for M-ARKO mice) were evident between groups during high-fat feeding. Liver weight was greater in M-ARKO than that in WT mice (1.5 ± 0.1 g vs 1.3 ± 0.0 g, respectively, P = 0.02). Finally, M-ARKO mice did not exhibit impairments in glucose tolerance or insulin sensitivity relative to WT mice at any study time point. In aggregate, these findings suggest that AR signaling specifically in monocytes/macrophages does not contribute to the regulation of systemic energy balance, adiposity, or insulin sensitivity in male mice.

Perspective beyond Cancer Genomics: Bioenergetics of Cancer Stem Cells

Although the notion that cancer is a disease caused by genetic and epigenetic alterations is now widely accepted, perhaps more emphasis has been given to the fact that cancer is a genetic disease. It should be noted that in the post-genome sequencing project period of the 21st century, the underlined phenomenon nevertheless could not be discarded towards the complete control of cancer disaster as the whole strategy, and in depth investigation of the factors associated with tumorigenesis is required for achieving it. Otto Warburg has won a Nobel Prize in 1931 for the discovery of tumor bioenergetics, which is now commonly used as the basis of positron emission tomography (PET), a highly sensitive noninvasive technique used in cancer diagnosis. Furthermore, the importance of the cancer stem cell (CSC) hypothesis in therapy-related resistance and metastasis has been recognized during the past 2 decades. Accumulating evidence suggests that tumor bioenergetics plays a critical role in CSC regulation; this finding has opened up a new era of cancer medicine, which goes beyond cancer genomics.

Influencia del mérito genético para la producción de leche en un hato holstein sobre el balance energético, indicadores del metabolismo energético y la reactivación ovárica posparto / Influence of genetic merit for milk production of a holstein herd, on energy balance, metabolic profiles and the postpartum ovarian resumption

El propósito de este trabajo fue determinar la influencia del mérito genético para la producción de leche sobre el balance energético, los indicadores del metabolismo energético y la reactivación ovárica posparto. Para este estudio, se utilizaron 10 vacas Holstein puras de diferente mérito genético para la producción de leche, que se alimentan bajo un sistema de pastoreo rotacional con suplementación de concentrado. A estos animales se les realizó un seguimiento durante los 10.4 (± 2.5), 21.6 (± 4.3), 31.8(± 4.5), 42.3 (± 4.2), y 51.9 (± 3.9) días posparto, los cuales constituyeron los periodos de muestreo. En cada muestreo, los animales fueron pesados con cinta métrica, se les evaluó la con se estimó su balance de energía. Además, se tomaron muestras de suero sanguíneo para evaluar las concentraciones de glucosa y colesterol; y se efectuó un seguimiento de la reactivación ovárica por ultrasonografía. La mayoría de las vacas reiniciaron su actividad ovárica en la segunda semana posparto y más de la mitad presentaron su primera ovulación durante el periodo experimental. Se encontró una relación estadísticamente significativa (p<0.05) y con pendiente negativa entre el mérito genético para la producción de leche y la magnitud del nadir del BEN, sin embargo el mérito genético no tuvo influencia significativa sobre los días al nadir del BEN, dado que las vacas de mérito genético alto, como bajo incrementaron el consumo y la producción de leche siguiendo patrones similares, pero con magnitudes diferentes. De igual forma el merito genético no se relacionó significativamente con los días a la primera ovulación. Además, ninguna de las variables del balance de energía, ni los metabolitos sanguíneos afectaron los días a la primera ovulación o el número de folículos clasificados por tamaño.

The aim of this research was to establish the genetic merit for milk yield influence on energy balance, energy metabolic profiles and the postpartum ovarian resumption. In this research, 10 pure-Holstein Friesian dairy cows, varying in genetic merit values for milk yield and fed on a rotational-grazing system with a supplementary concentrate ration were used. A serial of examinations were performed on10.4 (± 2.5), 21.6 (± 4.3), 31.8 (± 4.5), 42.3 (± 4.2), and 51.9 (± 3.9) postpartum days. In every sampling day animals were weighed by tape measure, their body condition score were calculated and the energy balance was estimated for every cow. In addition, blood serum tests were performed to analyze glucose and cholesterol blood concentration and an ultrasonographic assessment was executed to determine ovarian resumption. Nearly all cows had an ovarian resumption on the second week postpartum and more than a half had shown their first postpartum ovulation on the trial period. The genetic merit values for milk yield were not related with production values, therefore, the dependent variables of milk yield did not fluctuated with genetic merit. There was a significant negative relationship (p<0.05) between genetic merit for milk production and the nadir extent of net energy balance (NEB). Although, the genetic merit did not have significant influence on the number of days between calving to the nadir-attaining day, because high genetic merit cows as low genetic merit cows increased the intake and milk yield following similar patterns, but with different extents. In the same way, the genetic merit did not have significant relationship with the interval of calving to first ovulation. Furthermore, no one of the energy balance variables or blood metabolites influenced the interval of calving to first ovulation or the amount of follicles classified by size.

The role of thyroid hormone calorigenesis in the redox regulation of gene expression

Thyroid hormone (TH; 3,3',5-triiodothyronine, T3) is required for the normal function of most tissues, with major effects on 0(2) consumption and metabolic rate. These are due to transcriptional activation of respiratory genes through the interaction of T3-liganded TH receptors with TH response elements or the activation of intermediate factors, with the consequent higher production of reactive 0(2) species (ROS) and antioxidant depletion. T3-induced oxidative stress in the liver triggers the redox upregulation of the expression of cytokines (tumor necrosis factor-alfa [TNF-alfa], interleukin-10), enzymes (inducible nitric oxide synthase, manganese superoxide dismutase), and anti-apoptotic proteins (Bcl-2), via a cascade initiated by TNF-alfa produced by Kupffer cells, involving inhibitor of kB phosphorylation and nuclear factor-kB activation. Thus, TH calorigenesis triggers an expression pattern that may represent an adaptive mechanism to re-establish redox homeostasis and promote cell survival under conditions of ROS toxicity secondary to TH-induced oxidative stress. Mechanisms of expression of respiratory and redox-sensitive genes may be functionally integrated, which could be of importance to understand the complexities of TH action and the outcome of thyroid gland dysfunction.

Energetic metabolism of Chromobacterium violaceum

Chromobacterium violaceum is a free-living microorganism, normally exposed to diverse environmental conditions; it has a versatile energy-generating metabolism. This bacterium is capable of exploiting a wide range of energy resources by using appropriate oxidases and reductases. This allows C. violaceum to live in both aerobic and anaerobic conditions. In aerobic conditions, C. violaceum is able to grow in a minimal medium with simple sugars, such as glucose, fructose, galactose, and ribose; both Embden-Meyerhoff, tricarboxylic acid and glyoxylate cycles are used. The respiratory chain supplies energy, as well as substrates for other metabolic pathways. Under anaerobic conditions, C. violaceum metabolizes glucose, producing acetic and formic acid, but not lactic acid or ethanol. C. violaceum is also able to use amino acids and lipids as an energy supply

Influencia genética en requerimientos de energía. III. Herencia multifactorial modulada por género / Genetic influence on energy requeriments. III. multifictorial inheritence modulated by gender

Se utilizó un índice de conversión (IC) como medida de la eficiencia de utilización de la energía de la dieta y se observó que se distribuye conforme a una curva normal en ratas Wistar. Se confirmaron nuestras observaciones previas de que las ratas macho son mejores convertidoras de energía que las hembras. Se evaluó la hipótesis de que la herencia de la regulación de requerimientos nutricios es de tipo multifactorial. Para ello se cruzaron ratas F1 con IC alto (malas convertidoras) y se midió el IC en las crías F2. Las crías F2 machos se comportaron de acuerdo a la hipótesis ya que tuvieron IC más alto que los machos F1, o sea, resultaron peores convertidores de energía. Pero esto no ocurrió en las hembras en que las F2 fueron mejores convertidoras que las F1. Por ahora, no tenemos explicación para este comportamiento en función de género

Análisis energético y cineantropométrico de la pelota nacional

Fueron estudiados diez deportistas varones seleccionados de Pichincha de la disciplina de pelota nacional, modalidad cerda. Se realizó pruebas ergométricas consistentes en test de bruce e impulsión vertical (jump test; cuyos resultados fueron comparados con datos de otras disciplinas deportivas y correlacionadas con observaciones de campo, tratando de definir la vía metabólica utilizada por esta actividad deportiva. Se concluye que la pelota nacional es un deporte con gasto energético anaeróbico aláctico. En forma complementaria se analiza los resultados cineantropométricos que arrojan datos concernientes al porcentaje de grasa, peso muscular y exceso de peso equivalenetes a individuos sedentarios...

Influencia genética sobre los requerimientos de energía: I desarrollo de un modelo experimental / Genetic variation of energy requirements: I development of an experimental model

Se presentan los resultados obtenidos en el desarrollo de un modelo animal para estudiar la variación individual en requerimientos de energía, partiendo del postulado de que los requerimientos nutricios son determinados genéticamente pero su expresión, como fenotipos distintos, está condicionada por factores ambientales. Se partió del cruzamiento sucesivo de ratas Wistar machos y hembras "buenos" y "malos" convertidores de energía. La primera generación dió tres machos y cinco hembras cuya mediana de índice de conversión (IC) fue de 2.90 y extremos de 2.54 y 3.25. Al observar los valores individuales se hizo aparente que la proporción de machos con IC abajo de la mediana era 3/3 y para las hembras 2/5; esta distribución llevó a considerar si los machos fueran mejores utilizadores de energía que las hembras, al necesitar ingerir menos alimentos para aumentar su peso. Esta hipótesis se exploró cuantificando el IC en 91 ratas.La proporción de machos por arriba de la mediana (33/38) contrastó significativamente (p menor que 0.0001) con la proporción 13/53 encontrada en las hembras. La prueba de ratas (Z = 5.47, p = 0.00003) rechaza la probabilidad de sesgo de entrada por series. La diferencia de utilización en función del sexo hizo que se buscaran si el fenómeno es general para la rata o únicamente para la cepa Wistar. Experimentos con cepas Brown-Norway y Lewis mostraron resultados iguales: los machos eran mejores convertidores de energía. Los datos de Campbell y Taverner en cerdos machos castrados apoyan los del presente informe y la sugerencia de que el modelo de liga al sexo pudiera ser adecuado para estudiar mecanismos de variación de los requerimientos energéticos.