Prolonged changes in hepatic mitochondrial activity and insulin sensitivity by high fructose intake in adolescent rats

Persistence of damage induced by unhealthy diets during youth has been little addressed. Therefore, we investigated the impact of a short-term fructose-rich diet on liver metabolic activity in adolescent rats and the putative persistence of alterations after removing fructose from the diet. Adolescent rats were fed a fructose-rich diet for three weeks and then switched to a control diet for further three weeks. Body composition and energy balance were not affected by fructose-rich diet, while increased body lipids and lipid gain were found after the rescue period. Switching to a control diet reversed the upregulation of plasma fructose, uric acid, lipocalin, and haptoglobin, while plasma triglycerides, alanine aminotransferase, lipopolysaccharide, and tumor necrosis factor alpha remained higher. Hepatic steatosis and ceramide were increased by fructose-rich diet, but reversed by returning to a control diet, while altered hepatic response to insulin persisted. Liver fatty acid synthase and stearoyl-CoA desaturase (SCD) activities were upregulated by fructose-rich diet, and SCD activity remained higher after returning to the control diet. Fructose-induced upregulation of complex II-driven mitochondrial respiration, peroxisome proliferator-activated receptor-gamma coactivator 1 alpha, and peroxisome proliferator activated receptor alpha also persisted after switching to control diet. In conclusion, our results show prolonged fructose-induced dysregulation of liver metabolic activity

Prolonged changes in hepatic mitochondrial activity and insulin sensitivity by high fructose intake in adolescent rats

Persistence of damage induced by unhealthy diets during youth has been little addressed. Therefore, we investigated the impact of a short‐term fructose‐rich diet on liver metabolic activity in adolescent rats and the putative persistence of alterations after removing fructose from the diet. Adolescent rats were fed a fructose‐rich diet for three weeks and then switched to a control diet for further three weeks. Body composition and energy balance were not affected by fructose‐rich diet, while increased body lipids and lipid gain were found after the rescue period. Switching to a control diet reversed the upregulation of plasma fructose, uric acid, lipocalin, and haptoglobin, while plasma triglycerides, alanine aminotransferase, lipopolysaccharide, and tumor necrosis factor alpha remained higher. Hepatic steatosis and ceramide were increased by fructose‐rich diet, but reversed by returning to a control diet, while altered hepatic response to insulin persisted. Liver fatty acid synthase and stearoyl‐CoA desaturase (SCD) activities were upregulated by fructose‐rich diet, and SCD activity remained higher after returning to the control diet. Fructose‐induced upregulation of complex II‐driven mitochondrial respiration, peroxisome proliferator‐activated receptor‐gamma coactivator 1 alpha, and peroxisome proliferator activated receptor α also persisted after switching to control diet. In conclusion, our results show prolonged fructose‐induced dysregulation of liver metabolic activity

Fructose removal from the diet reverses inflammation, mitochondrial dysfunction, and oxidative stress in hippocampus

Young age is often characterized by high consumption of processed foods and fruit juices rich in fructose, which, besides inducing a tendency to become overweight, can promote alterations in brain function. The aim of this study was therefore to (a) clarify brain effects resulting from fructose consumption in juvenile age, a critical phase for brain development, and (b) verify whether these alterations can be rescued after removing fructose from the diet. Young rats were fed a fructose-rich or control diet for 3 weeks. Fructose-fed rats were then fed a control diet for a further 3 weeks. We evaluated mitochondrial bioenergetics by high-resolution respirometry in the hippocampus, a brain area that is critically involved in learning and memory. Glucose transporter-5, fructose and uric acid levels, oxidative status, and inflammatory and synaptic markers were investigated by Western blotting and spectrophotometric or enzyme-linked immunosorbent assays. A short-term fructose-rich diet induced mitochondrial dysfunction and oxidative stress, associated with an increased concentration of inflammatory markers and decreased Neurofilament-M and post-synaptic density protein 95. These alterations, except for increases in haptoglobin and nitrotyrosine, were recovered by returning to a control diet. Overall, our results point to the dangerous effects of excessive consumption of fructose in young age but also highlight the effect of partial recovery by switching back to a control diet

Hallazgos arqueológicos en la Quebrada de Zapagua : (Departamento de Humahuaca, provincia de Jujuy)

Fil: Cigliano, Eduardo M.. Universidad Nacional de La PlataFil: Calandra, Horacio A.. Universidad Nacional de La Plat

Species delimitation in the Andean grasshopper genus <i>Orotettix</i> Ronderos & Carbonell (Orthoptera: Melanoplinae): an integrative approach combining morphological, molecular and biogeographical data

The reciprocal illumination nature of integrative taxonomy through hypothesis testing, corroboration and revision is a powerful tool for species delimitation as more than one source has to support the hypothesis of a new species. In this study, we applied an integrative taxonomy approach combining molecular and morphological data sets with distributional patterns to examine the level of differentiation between and within the grasshopper Orotettix species. Orotettix was described based on five valid species distributed in the Andes of Peru. In our study, initially a molecular-based hypothesis was postulated and tested against morphological data and geographical patterns of distribution. Results from molecular and morphological analyses showed agreement among the species delimitation in Orotettix, and were also consistent with the geographical distribution. The analyses allowed us to delimit five new species for the genus (O. lunatus sp. nov., O.astreptos sp. nov., O. colcaensis sp. nov., O.paucartambensis sp. nov. and O.dichrous sp. nov.) from the Eastern and Western Cordilleras of Peru. We also provide critical knowledge on the phylogenetic relationships and distribution of the genus and conduct a revision of Orotettix.Facultad de Ciencias Naturales y MuseoCentro de Estudios Parasitológicos y de Vectore

Haptoglobin binding to apolipoprotein A-I prevents damage from hydroxyl radicals on its stimulatory activity of the enzyme lecithin-cholesterol acyl-transferase

Apolipoprotein A-I (ApoA-I), a major component of HDL, binds Haptoglobin, a plasma protein transporting to liver or macrophages free Hb for preventing hydroxyl radical production. This work aimed to assess whether Haptoglobin protects ApoA-I against this radical. Human ApoA-I structure, as analyzed by electrophoresis and MS, was found severely altered by hydroxyl radicals in vitro. Lower alteration of ApoA-I was found when HDL was oxidized in the presence of Haptoglobin. ApoA-I oxidation was limited also when the complex of Haptoglobin with both high density lipoprotein and Hb, immobilized on resin beads, was exposed to hydroxyl radicals. ApoA-I function to stimulate cholesterol esterification was assayed in vitro by using ApoA-I-containing liposomes. Decreased stimulation was observed when liposomes oxidized without Haptoglobin were used. Conversely, after oxidative stress in presence of Haptoglobin (0.5 microM monomer), the liposome activity did not change. Plasma of Carrageenan-treated mice was analyzed by ELISA for the levels of Haptoglobin and ApoA-I, and used to isolate HDL for MS analysis. Hydroxyproline-containing fragments of ApoA-I were found associated with low levels of Haptoglobin (18 microM monomer), whereas they were not detected when the Haptoglobin level increased (34-70 microM monomer). Therefore Haptoglobin, when circulating at enhanced levels with free Hb during the acute phase of inflammation, might protect ApoA-I structure and function against hydroxyl radicals

Species delimitation in the Andean grasshopper genus <i>Orotettix</i> Ronderos & Carbonell (Orthoptera: Melanoplinae): an integrative approach combining morphological, molecular and biogeographical data

The reciprocal illumination nature of integrative taxonomy through hypothesis testing, corroboration and revision is a powerful tool for species delimitation as more than one source has to support the hypothesis of a new species. In this study, we applied an integrative taxonomy approach combining molecular and morphological data sets with distributional patterns to examine the level of differentiation between and within the grasshopper Orotettix species. Orotettix was described based on five valid species distributed in the Andes of Peru. In our study, initially a molecular-based hypothesis was postulated and tested against morphological data and geographical patterns of distribution. Results from molecular and morphological analyses showed agreement among the species delimitation in Orotettix, and were also consistent with the geographical distribution. The analyses allowed us to delimit five new species for the genus (O. lunatus sp. nov., O.astreptos sp. nov., O. colcaensis sp. nov., O.paucartambensis sp. nov. and O.dichrous sp. nov.) from the Eastern and Western Cordilleras of Peru. We also provide critical knowledge on the phylogenetic relationships and distribution of the genus and conduct a revision of Orotettix.Facultad de Ciencias Naturales y MuseoCentro de Estudios Parasitológicos y de Vectore

Influence of Weather Variables and Plant Communities on Grasshopper Density in the Southern Pampas, Argentina

A study was conducted to evaluate the influence of weather (precipitation and temperature) and plant communities on grasshopper density over a 14-year period (1996–2009) in Benito Juárez County, Southern Pampas, Argentina. Total density strongly varied among plant communities. Highest values were registered in 2001 and 2003 in highly disturbed pastures and in 2002 and 2009 in halophilous grasslands. Native grasslands had the lowest density values. Seasonal precipitation and temperature had no significant effect on total grasshopper density. Dichroplus elongatus (Giglio-Tos) (Orthoptera: Acridoidea), Covasacris pallidinota (Bruner), Dichroplus pratensis Bruner, Scotussa lemniscata Stål, Borellia bruneri (Rehn) and Dichroplus maculipennis (Blanchard) comprised, on average, 64% of the grasshopper assemblages during low density years and 79% during high density years. Dichroplus elongatus, S. lemniscata and C. pallidinota were the most abundant species in 2001, 2002 and 2003, while D. elongatus, B. brunneri and C. pallidinota in 2009. Dichroplus elongatus and D. pratensis, mixed feeders species, were positively affected by summer rainfall. This suggests that the increase in summer precipitation had a positive effect on the quantity and quality forage production, affecting these grasshopper populations. Scotussa lemniscata and C. pallidinota were negatively affected by winter and fall temperature, possibly affecting the embryonic development before diapause and hatching. Dichroplus elongatus and D. pratensis were associated with highly disturbed pastures, S. lemniscata with pastures and B. bruneri and D. maculipennis with halophilous grasslands. Covasacris pallidinota was closely associated with halophilous grasslands and moderately disturbed pastures. Weather conditions changed over the years, with 2001, 2002 and 2003 having excessive rainfall while 2008 and 2009 were the driest years since the study started. We suggest that although seasonal precipitation and temperature had no significant effect on total grasshopper density, these weather variables and plant communities had differential influence on the dominant grasshopper species