Guf1 overexpression improves pancreatic β cell functions in type 2 diabetes mellitus rats with Roux-en-Y gastric bypass (RYGB) surgery

The Roux-en-Y gastric bypass (RYGB) is a one-of-a-kind treatment among contemporary bariatric surgical procedures, and its therapeutic effects for type 2 diabetes mellitus (T2DM) are satisfactory. The present study performed isobaric tags for relative and absolute quantification (iTRAQ) combined with liquid chromatography-tandem mass spectrometry (LC–MS/MS) analysis identifying different proteomics between T2DM rats with or without Roux-en-Y gastric bypass (RYGB) surgery, and GTP binding elongation factor GUF1 (Guf1) was first found to be significantly upregulated in rats from the T2DM plus RYGB group. In the cellular lipotoxicity model induced by palmitic acid stimulation of rat pancreatic beta cell line, INS-1, palmitic acid treatment inhibited cell viability, suppressed GSIS, promoted lipid droplet formation, promoted cell apoptosis, and induced mitochondrial membrane potential loss. The effects of palmitic acid on INS-1 cells mentioned above could be partially eliminated by Guf1 overexpression but aggravated by Guf1 knockdown. Last, under palmitic acid treatment, Guf1 overexpression promotes the PI3K/Akt and NF-κB signaling but inhibits the AMPK activation. Guf1 is upregulated in T2DM rats who received RYGB, and Guf1 overexpression improves cell mitochondrial functions, increases cell proliferation, inhibits cell apoptosis, and promotes cell functions in palmitic acid-treated β cells. (AU)

Renal tubule ectopic lipid deposition in diabetic kidney disease rat model and in vitro mechanism of leptin intervention

Diabetic kidney disease (DKD) is a major health burden closely related to lipid metabolism disorders. Leptin has lipid-lowering efficacy, but the specific mechanism of its local effects on kidney is still unclear. This study aims to investigate the role of ectopic lipid deposition (ELD) in DKD and evaluate the lipid-lowering efficacy of leptin in the palmitic acid (PA)-induced renal tubular epithelial cells (NRK-52E). DKD model was established in Sprague–Dawley (SD) rats by giving single intraperitoneal injection of streptozotocin (STZ, 30 mg/kg) after high-fat diet for 8 weeks. Then, the expression changes of lipid metabolism-related markers were observed. At week 12, the protein expression level of lipid-deposited marker adipose differentiation-related protein (ADRP) was significantly increased. Besides, the lipid synthesis marker sterol regulatory element-binding protein 1c (SREBP 1c) was highly expressed while the expression of insulin-induced gene 1 (Insig-1), a key molecular of inhibiting SREBP 1c, was decreased. Leptin and compound c were incubated with the PA-induced NRK-52E cells to investigate the lipid-lowering effects and whether this effect was mediated by the AMPK/Insig-1/SREBP 1c signaling pathways. mRNA and protein of ADRP and SREBP 1c were reduced after leptin treatment, while Insig-1 and phosphorylated AMP-activated protein kinase (AMPK) were increased. Conversely, inhibition of AMPK phosphorylation by compound c mostly eliminated lipid-lowering efficacy of leptin in PA-induced cells. Collectively, these results suggested that there was ELD of renal tubular epithelial cells in DKD rats. Leptin upregulated the expression level of Insig-1 by activating AMPK to attenuate ELD in PA-induced NRK-52E cells. (AU)

Preventive effect of oleate on palmitate-induced insulin resistance in skeletal muscle and its mechanism of action

Insulin resistance in skeletal muscle is a feature associated with exposure to an excess of saturated fatty acids such as palmitate. Oleic acid has been shown to blunt palmitate-induced insulin resistance in muscle cells. However, there is no literature available regarding the effect of oleic acid on palmitate-induced insulin resistance in intact muscle. Therefore, this study investigated the effect of oleic acid on palmitate-induced insulin resistance in rat soleus muscle and its underlying mechanisms. For these purposes, oleic acid (1 mM) was administered for 12 h in the absence or presence of palmitate (2 mM). At the end of the experiment, plasmalemmal GLUT4, the phosphorylation of AS160 and Akt-2, and the total expression of these signaling proteins were examined. We found that treatment with palmitate for 12 h reduced insulin-stimulated GLUT4 translocation and the phosphorylation of AS160 and Akt-2. However, the administration of oleic acid fully restored insulin-stimulated GLUT4 translocation (P < 0.05), as well as AS160 and Akt-2 phosphorylation (P < 0.05) despite the continuous presence of palmitate. Wortmannin, an inhibitor of PI3-K, only slightly prevented the oleic acid-induced improvements in insulin-stimulated GLUT4 translocation, and AS160 phosphorylation. However, this treatment completely inhibited the oleic acid-induced improvement in insulin-stimulated Akt-2 phosphorylation. In contrast, the oleic acid-induced improvement in insulin signaling was not affected by compound C, an AMPK specific inhibitor. In conclusion, the results clearly indicate that oleic acid administration alleviates palmitate-induced insulin resistance by promoting GLUT4 translocation in muscle, at least in part, by activating the PI3K pathway

Omega-3 fatty acids control productions of superoxide and nitrogen oxide and insulin content in INS-1E cells

Omega-3 fatty acids have multiple effects in peripheral tissues and pancreatic beta cell function. Dietary depletion of omega-3 fatty acids is associated with pancreatic islet dysfunction and insulin resistance in rats. Herein, the effects of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) on pancreatic beta cell redox state and function were investigated. INS-1E insulin-secreting cells were incubated with EPA and DHA in combination with palmitic acid, and productions of reactive oxygen species (ROS), nitric oxide (NO) and insulin were measured. The involvement of the NADPH oxidase complex in ROS production and expression of the antioxidant enzymes was also investigated. After incubation for 1 or 48 h, productions of superoxide (by hydroethidine method), nitric oxide (by 4,5-diaminofluorescein diacetate-DAF-2DA assay), insulin (by radioimmunoassay), and expressions (by western blot analysis) of glutathione peroxidase (GPx-1) and gp91PHOX were measured. EPA and DHA reduced superoxide production after 1-h incubation. After 48 h, palmitic acid reduced superoxide production that was normalized by EPA treatment. Palmitic acid increased NO production that was reverted by EPA and DHA. Palmitic acid increased insulin secretion after 48 h, whereas both omega-3 fatty acids increased intracellular insulin content. EPA and DHA enhanced GPx-1 expression as well as gp91PHOX glycosylated form. In conclusion, EPA and DHA increased intracellular insulin content and antioxidant enzymatic defense capacity and decreased pro-oxidant generating activities that are associated with maintenance of pancreatic beta cell redox state in response to palmitic acid (AU)

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Evaluación y establecimiento de las especificaciones de calidad del pool de aceite de hígado de tiburón / Evaluation and establishment of quality specifications to pool of sharks liver oil

Objetivo: Calcular experimentalmente los límites de especificación de calidad para el pool de aceite de hígado de tiburones costeros de Cuba, a través del método de la K tabulada. Materiales y métodos: Se realizó el análisis, a diez lotes consecutivos, de los parámetros peso específico, índice de refracción, acidez, saponificación, peróxido, materia insaponificable y contenido de vitamina A y ácido palmítico. Se evaluó la distribución y la aleatoriedad de los datos y posteriormente se calcularon los límites de especificación de calidad por el método de la K tabulada, para un 95% de confianza. Resultados: Los valores obtenidos en la evaluación de los parámetros físico - químicos demostraron la calidad del aceite, cumpliendo la distribución normal y aleatoriedad de los datos, con valores de probabilidad superiores a 0,05. Conclusiones: Empleando el método de la K tabulada se establecieron límites de especificación unilaterales para el índice de acidez, contenido de vitamina A y ácido palmítico, mientras que para el peso específico, índices de refracción, saponificación, peróxido y materia insaponificable fueron bilaterales. Los lotes del pool de aceite hígado de tiburón poseen adecuada calidad, considerando los resultados de los parámetros evaluados. Se demostró que existe un alto grado de conformidad en las propiedades entre los lotes evaluados

Aims: The objective was to experimentally determine the quality specification limits for the pool of shark-liver oil from Cuban coastal sharks, by using the tabulated K method. Materials and methods: Using ten consecutive lots, an analysis was carried out of parameters such as specific weight, refractive indexes, acidity, saponification, peroxide, unsaponifiable matter, and vitamin A and palmitic acid content. The distribution and randomness of the data was assessed. Then, the quality specification limits were calculated, for a 95% degree of confidence. Results: The values obtained in the assessment of physical and chemical parameters demonstrated the quality of the oil, by adhering to the normal distribution and randomness of data, with probability values above 0,05. Conclusions: Using the tabulated K method were established unilateral quality specification limits to index of acidity and vitamin A and palmitic acid content, while to specific weight, refractive indexes, saponification, peroxide and unsaponifiable matter were bilateral. The assessed lots of pool shark-liver oil have adequate quality, considering the results of the evaluated parameters. The properties of the assessed lots showed a high degree of compliance

Interaction of Palmitic Acid with Losartan Potassium at the Binding Sites of Bovine Serum Albumin

The binding of losartan potassium, an angiotensin II receptor antagonist, to bovine serum albumin wasstudied by equilibrium dialysis method (ED) in presence or absence of palmitic acid. The study wascarried out using ranitidine and diazepam as site-1 and site-2 specific probe, respectively. Differentanalysis of binding of losartan to bovine serum albumin suggested two sets of association constants:high affinity association constant (k1 = 11.2 x 105 M-1) with low capacity (n1 = 2) and low affinityassociation (k2 = 2. 63 x 105 M-1) constant with high capacity (n2 = 10) at pH 7.4 and 27°C. Duringconcurrent administration of palmitic acid and losartan potassium in presence or absence of ranitidineor diazepam, it was that found that palmitic acid causes the release of losartan potassium from itsbinding site on BSA resulting reduced binding of losartan potassium to BSA. The increment in freefraction of losartan potassium was from 13.1% to 47.2 % upon the addition of increased concentrationof only palmitic acid at a concentration of 0 x 10-5 M to 16 x 10-5 M. In presence of ranitidine ordiazepam as site specific probes, palmitic acid further increases the free fraction of losartan potassiumwere from 22.8% to 53.4% and 35.3 to 65.5%, respectively. This data provided the evidence ofinteraction of higher concentration of palmitic acid at the binding sites on BSA changing thepharmacokinetics properties of losartan potassium(AU)

Recientes avances en fórmulas infantiles / Recent advances in infant formulas

La alimentación durante los primeros meses de vida tiene una gran importancia tanto en las fases tempranas del desarrollo como en su salud a largo plazo. La Organización Mundial de la Salud señala que la lactancia materna exclusiva es el alimento ideal para el recién nacido a término sano desde el nacimiento hasta los 6 meses de edad. Cuando una madre no puede amamantar a su hijo, las fórmulas infantiles constituyen la mejor alternativa como fuente de alimentación. A medida que hemos ido conociendo mejor las necesidades nutricionales del lactante, se ha ido modificando la composición de las fórmulas. Se han añadido nuevos ingredientes funcionales en el intento de hacerlas más semejantes a la leche humana. En la presente revisión se comentará el interés nutricional y funcional de los avances más recientes en las fórmulas infantiles para lactantes sanos, como son la adición de alfalactoalbúmina, ácidos grasos poliinsaturados de cadena larga, palmítico en posición beta, nucleótidos, oligosacáridos con efecto prebiótico y los probióticos (AU)

Feeding during the first months of life has a decisive influence not only on early developmental phases in infants but also in their long-term health. The World Health Organization points out that exclusive breastfeeding is the ideal feeding from birth to sixth months of age in the healthy term newborn. When a mother cannot breastfeed her offspring, infant formulas stay as a good alternative for infant feeding. The deeper our knowledge on the nutritional needs of infants the more precise the composition of infant formulas. New functional ingredients have been incorporated to paediatric milk formulas with the goal of mimicking the functional properties of human milk. In the present article we review the most recent advances in infant formulas: alpha-lactalbumin, polyunsaturated fatty acids, beta-palmitate, nucleotides, prebiotic oligosaccharides and probiotics (AU)

Emulsiones líquida-cristalinas estabilizadas con estearato de trietanolamina y ácido esteárico: influencia del método de preparación en las propiedades y en la formación de gotas secundarias / Stabilized liquid-crystalline emulsions with triethanolamine stearate and stearic acid: preparation method influence in the properties and formation of secondary droplets

Se desarrolló una metodología que permite obtener emulsiones de vaselina líquida estabilizadas con estearato de trietanolamina y ácido esteárico con características líquida-cristalinas en las que las gotas se agrupan formando gotas secundarias de unos 15 mcrom de diámetro. La formación de estas gotas secundarias, que es una consecuencia de la presencia de cristales líquidos lioptrópicos en las emulsiones, trae como consecuencia una disminución de la viscosidad. El reemplazo de parte de la vaselina líquida de estas emulsiones por otros emolientes de mayor capacidad de penetración dérmica, tales como el miristato de isopropilo y el 2-octil-1-dodecanol, no disminuye las características líquida-cristalinas, lo que permite obtener otras emulsiones más adecuadas para usos farmacéutico y cosmético

It has been developed a methodology which allows obtaining mineral oil emulsions stabilized with triethanolamine stearate and stearic acid with liquid-crystalline characteristics where droplets cluster themselves forming secondary droplets of 15 microm diameter. The formation of the mentioned secondary droplets, which are a consequence of the presence of lyotropic liquid crystals in the emulsions, produces a diminution of the viscosity. The replacement of part of the mineral oil of these emulsions for others emollients with greater dermal penetration capacity, such as isopropyl myristate and 2-octyl-1-dodecanol, does not diminish the liquid-crystalline characteristics, granting the obtainment of more adequate emulsions for pharmaceutical and cosmetic usage

Valoración no invasiva de la administración en recién nacidos y lactantes afetados por cólicos de lactante de una fórmula de inicio y de otra adicionada / Noninvassive assessment of the administration of on initial formula, to be supplemented with another, to newborns and infants with infantile colic

La alimentación de recién nacidos y lactantes con síndrome del cólico lactante, con una leche especial a la que se ha añadido: - Betapol, grasa especial con gran proporción de ácido palmítico en posición beta. del triglicérido, - Componente proteico parcialmente hidrolizado de seroproteína de leche de vaca.- Fructoligosacáridos; mejoran la sintomatología, reducen la esteatorrea y mejoran el estreñimiento, con un aumento significativo del liquido fecal, sin inducir malabsorción de los hidratos de carbono (AU)