Victoriano Pérez-Vázquez

A PPARγ, NF-κB and AMPK-Dependent Mechanism May Be Involved in the Beneficial Effects of Curcumin in the Diabetic db/db Mice Liver

Turmeric (Curcuma longa) is a rhizomatous herbaceous perennial plant of the ginger family which has been used to treat biliary disorders, anorexia, cough, rheumatism, cancer, sinusitis, hepatic disorders, hyperglycemia, obesity, and diabetes in both Ayurvedic and Traditional Chinese Medicine. Suggested mechanisms of action include the modulation of signal transduction cascades and effects on gene expression, however they remain to be elucidated. In this study, the expression of some proteins responsible for transcription factors, inflammation, and metabolic control were evaluated by western blot in 15-week-old db/db mice livers treated with curcumin 0.75% mixed in their diet for 8 weeks. In addition, nitrosative stress was evaluated. Curcumin increased the expression of AMPK and PPARγ, and diminished NF-κB protein in db/db mice. However, it did not modify the expression of PGC-1α or SIRT1. Nitrosative stress present in db/db mice livers was determined by a unique nitrotyrosylated protein band (75 kDa) and was not reverted with curcumin. In conclusion, curcumin regulates the expression of AMPK, PPARγ, and NF-κB; suggesting a beneficial effect for treatment of T2DM complications. In order to observe best beneficial effects it is desirable to administer curcumin in the earlier states of T2DM.

The Saccharomyces cerevisiae mitochondrial unselective channel behaves as a physiological uncoupling system regulated by Ca2+, Mg2+, phosphate and ATP.

It is proposed that the Saccharomyces cerevisiae the Mitochondrial Unselective Channel (ScMUC) is tightly regulated constituting a physiological uncoupling system that prevents overproduction of reactive oxygen species (ROS). Mg2+, Ca2+ or phosphate (Pi) close ScMUC, while ATP or a high rate of oxygen consumption open it. We assessed ScMUC activity by measuring in isolated mitochondria the respiratory control, transmembrane potential (ΔΨ), swelling and production of ROS. At increasing [Pi], less [Ca2+] and/or [Mg2+] were needed to close ScMUC or increase ATP synthesis. The Ca2+-mediated closure of ScMUC was prevented by high [ATP] while the Mg2+ or Pi effect was not. When Ca2+ and Mg2+ were alternatively added or chelated, ScMUC opened and closed reversibly. Different effects of Ca2+ vs Mg2+ effects were probably due to mitochondrial Mg2+ uptake. Our results suggest that ScMUC activity is dynamically controlled by both the ATP/Pi ratio and divalent cation fluctuations. It is proposed that the reversible opening/closing of ScMUC leads to physiological uncoupling and a consequent decrease in ROS production.

Curcumin restores mitochondrial functions and decreases lipid peroxidation in liver and kidneys of diabetic db/db mice

BackgroundNitrosative and oxidative stress play a key role in obesity and diabetes-related mitochondrial dysfunction. The objective was to investigate the effect of curcumin treatment on state 3 and 4 oxygen consumption, nitric oxide (NO) synthesis, ATPase activity and lipid oxidation in mitochondria isolated from liver and kidneys of diabetic db/db mice.ResultsHyperglycaemia increased oxygen consumption and decreased NO synthesis in liver mitochondria isolated from diabetic mice relative to the control mice. In kidney mitochondria, hyperglycaemia increased state 3 oxygen consumption and thiobarbituric acid-reactive substances (TBARS) levels in diabetic mice relative to control mice. Interestingly, treating db/db mice with curcumin improved or restored these parameters to normal levels; also curcumin increased liver mitochondrial ATPase activity in db/db mice relative to untreated db/db mice.ConclusionsThese findings suggest that hyperglycaemia modifies oxygen consumption rate, NO synthesis and increases TBARS levels in mitochondria from the liver and kidneys of diabetic mice, whereas curcumin may have a protective role against these alterations.

Differential Proteomic Analysis of the Pancreas of Diabetic db/db Mice Reveals the Proteins Involved in the Development of Complications of Diabetes Mellitus

Type 2 diabetes mellitus is characterized by hyperglycemia and insulin-resistance. Diabetes results from pancreatic inability to secrete the insulin needed to overcome this resistance. We analyzed the protein profile from the pancreas of ten-week old diabetic db/db and wild type mice through proteomics. Pancreatic proteins were separated in two-dimensional polyacrylamide gel electrophoresis (2D-PAGE) and significant changes in db/db mice respect to wild type mice were observed in 27 proteins. Twenty five proteins were identified by matrix-assisted laser desorption/ionization (MALDI) time-of-flight (TOF) and their interactions were analyzed using search tool for the retrieval of interacting genes/proteins (STRING) and database for annotation, visualization and integrated discovery (DAVID). Some of these proteins were Pancreatic α-amylase, Cytochrome b5, Lithostathine-1, Lithostathine-2, Chymotrypsinogen B, Peroxiredoxin-4, Aspartyl aminopeptidase, Endoplasmin, and others, which are involved in the metabolism of carbohydrates and proteins, as well as in oxidative stress, and inflammation. Remarkably, these are mostly endoplasmic reticulum proteins related to peptidase activity, i.e., they are involved in proteolysis, glucose catabolism and in the tumor necrosis factor-mediated signaling pathway. These results suggest mechanisms for insulin resistance, and the chronic inflammatory state observed in diabetes.

Aerobic training but no resistance training increases SIRT3 in skeletal muscle of sedentary obese male adolescents

Abstract In recent years, prevalence of obesity in children and adolescents has increased. A strategy for prevention and management of obesity is aerobic training (AT) due to its effectiveness to decrease fat mass. AT increases the content of SIRT3, a mitochondrial protein that increases the expression of PGC-1α and NFR1, thereby enhances mitochondrial function and metabolic health. Resistance training (RT) provides metabolic benefits but its effect on SIRT3 content is unknown. To compare the effect of AT and RT on SIRT3, PGC-1α and NRF-1 protein levels in skeletal muscle of sedentary obese adolescents. Twenty-seven sedentary obese male adolescents (age: 16.7 ± 0.9 years; BMI: 33.7 ± 4.3 kg/m2) completed a 1-month control period prior to randomization to one of two supervised exercise protocols: AT (3 days/week, 40 min/day, 70–80% peak heart rate) or RT (3 days/week, 11 exercises, 2 sets/exercise, 12 repetitions/set) for 12 weeks. Biopsies were obtained from the vastus lateralis muscle before and after 12 weeks to analyse SIRT3, PGC-1α and NRF-1 proteins content. Peak oxygen consumption (VO2peak) and anthropometric variables were evaluated before and after training. AT increased SIRT3 content, which was associated with improvements in PGC-1α content and body fat percentage. RT did not affect SIRT3 or PGC-1α. VO2peak increased only in AT. The increase in muscle mitochondrial SIRT3 was observed only following AT. In contrast, RT increased muscle mass without improving SIRT3 in obese male adolescents.

Ultraviolet light-C increases antioxidant capacity of the strawberry (Fragaria x ananassa) in vitro and in high-fat diet-induced obese rats

Abstract Flavonoids and polyphenols from the strawberry and other fruits have been proposed to reduce the oxidative stress produced by the obesity and her complications. Moreover, it has been proposed that irradiation with UV‐C to strawberry may increase the antioxidant capacity of this fruit. The aim of the present study was to explore the effects of the UV‐C on antioxidant capacity of strawberry in vitro and in vivo. Strawberry slices were irradiated with ultraviolet light‐C (UV‐C) at 1.2 W/m2/16.5 min; then, the power antioxidant was isolated from the nonirradiated and irradiated strawberry slices into an organic phase, which was lyophilized to finally producing a nonirradiated strawberry extract (NSE) and UV‐irradiated strawberry extract (UViSE) powder. After the antioxidant capacity of both extracts were determined in vitro using the Trolox equivalent antioxidant capacity (TEAC) assay and in vivo using high‐fat diet‐induced obese rats. Our results demonstrated that irradiation with UV‐C to strawberry slices increased the antioxidants content, which was corroborated in vitro, where the antioxidant capacity of UViSE was higher than the NSE. However, in obese rats, the reduction in the oxidative damage by the UViSE and NSE were similar in peripheral tissues. Interestingly, the UViSE was better than the NSE to reduce the oxidative damage in brain. In conclusion, UV‐irradiation increases the antioxidants content of strawberry that is correlated with an increased antioxidant capacity in vitro, but in rats, this antioxidant capacity may be more effective in brain than in peripheral tissues.

Protein Expression Profile of Twenty-Week-Old Diabetic db/db and Non-Diabetic Mice Livers: A Proteomic and Bioinformatic Analysis

Type 2 diabetes mellitus is characterized by insulin resistance in the liver. Insulin is not only involved in carbohydrate metabolism, it also regulates protein synthesis. This work describes the expression of proteins in the liver of a diabetic mouse and identifies the metabolic pathways involved. Twenty-week-old diabetic db/db mice were hepatectomized, after which proteins were separated by 2D-Polyacrylamide Gel Electrophoresis (2D-PAGE). Spots varying in intensity were analyzed using mass spectrometry, and biological function was assigned by the Database for Annotation, Visualization and Integrated Discovery (DAVID) software. A differential expression of 26 proteins was identified; among these were arginase-1, pyruvate carboxylase, peroxiredoxin-1, regucalcin, and sorbitol dehydrogenase. Bioinformatics analysis indicated that many of these proteins are mitochondrial and participate in metabolic pathways, such as the citrate cycle, the fructose and mannose metabolism, and glycolysis or gluconeogenesis. In addition, these proteins are related to oxidation–reduction reactions and molecular function of vitamin binding and amino acid metabolism. In conclusion, the proteomic profile of the liver of diabetic mouse db/db exhibited mainly alterations in the metabolism of carbohydrates and nitrogen. These differences illustrate the heterogeneity of diabetes in its different stages and under different conditions and highlights the need to improve treatments for this disease.

Mitochondrial content, oxidative, and nitrosative stress in human full-term placentas with gestational diabetes mellitus

BackgroundThe purpose of this study was to determine the mitochondrial content, and the oxidative and nitrosative stress of the placenta in women with gestational diabetes mellitus (GDM).MethodsFull-term placentas from GDM and healthy pregnancies were collected following informed consent. The lipid peroxidation (TBARS) and oxidized protein (carbonyls) levels were determined by spectrophotometry, and 3-nitrotyrosine (3-NT), subunit IV of cytochrome oxidase (COX4), adenosine 5′-monophosphate (AMP)–activated protein kinase (AMPK) and actin were determined by western blot, whereas ATPase activity was performed by determining the adenosine triphosphate (ATP) consumption using a High-performance liquid chromatography (HPLC) system.ResultsTBARS and carbonyls levels were lower in the placentas of women with GDM compared with the normal placentas (p < 0.001 and p < 0.05, respectively). Also, 3-NT/actin and AMPK/actin ratios were higher in GDM placentas than in the normal placentas (p = 0.03 and p = 0.012, respectively). Whereas COX4/actin ratio and ATPase activity were similar between GDM placentas and those controls.ConclusionsThese data suggest that placentas with GDM are more protected against oxidative damage, but are more susceptible to nitrosative damage as compared to normal placentas. Moreover, the increased expression levels of AMPK in GDM placentas suggest that AMPK might have a role in maintaining the mitochondrial biogenesis at normal levels.Trial registrationHGRL28072011. Registered 28 July 2011.