Apparent metabolizable energy and ileal amino acid digestibility of commercial soybean meals of different origins in broilers

We studied the chemical composition and the in vivo AMEn content and apparent (AID) and standardized (SID) ileal digestibility of CP and amino acids (AA) of 27 samples of soybean meals (SBM) from Argentina (ARG), Brazil (BRA), and USA, collected in Spain. On 88% DM basis, the BRA meals had more CP (46.9 vs. 46.0 and 45.9%; P < 0.05) and less sucrose (5.21 vs. 6.28 and 6.47%; P < 0.001) and stachyose (4.20 vs. 4.66 and 4.78%; P < 0.05) than the USA and ARG meals. Urease activity, protein dispersibility index, KOH protein solubility, and trypsin inhibitor activity values, were higher for the USA meals than for the South American meals (P < 0.05). In the in vivo trial, broilers received a common crumble diet from 0 to 16 d of age and then, their respective experimental diets (53% of a N-free diet and 47% of each of the 27 SBM tested) in mash form, for 5 d. The AMEn (2,334 vs. 2,282 and 2,277 kcal/kg; P = 0.062) and the AID (87.3 vs. 86.7 and 86.4%; P = 0.054) and SID (91.9 vs. 91.2 and 90.8%; P < 0.05) of the protein, were greater for the USA meals than for the ARG and BRA meals. In fact, the SID of Lys (93.5 vs. 93.0 and 92.1%; P < 0.001) and of the sum of Lys, Met, Thr, Trp, and Cys (91.4 vs. 91.0 and 90.2%; P < 0.05) were greater for the USA meals than for the ARG and BRA meals. In summary, the chemical composition, protein quality indicators, AMEn content, and ileal digestibility of the CP and the AA of the SBM, varied with the country of origin of the soybeans. In order to increase the accuracy of the feed formulation process, the composition and nutrient content of commercial batches of SBM, by country of origin should be controlled and periodically updated.

- Invited Review - Pig meat production in the European Union-27: current status, challenges, and future trends

The main objective of this study was to present data on the current situation and future trends of pig meat production in the European Union-27 (EU). Pig production has played an important social and economic role for centuries in many states of the EU. In 2022, pig meat production in the EU reached 23 M tons, which represented 21% of total production worldwide. The two key reasons that justify such amount of pork produced, are the acceptance and high consumption of the meat by the local population and the high quality of the meat produced which facilitated pork export. However, current data show a reduction in pork production for the last three years, as a consequence of a series of events that include i) problems with the chain of ingredients supply, ii) uncontrolled increase in African Swine Fever (ASF) outbreaks, iii) fast recovery of pig production in China, iv) increasing concerns by the rural population on the high cost to meet future requirements of the EU legislation on farm management, environmental sustainability and animal welfare, v) increased cost of all inputs involved in pig production and vi) limited interest of the new farmer generation to work on the pig sector. Consequently, pork production is expected to decrease in the EU for the next years, although sales will be maintained at a relative high level because pork is the meat preferred by local consumers in most EU countries. In order to maintain the favourable position of the pork industry in the near future, strategies to implement include: i) maintain the quality of the meat destinated to export markets, ii) improve the control of outbreaks of ASF and other swine diseases, iii) implementation of technological innovations to improve working conditions making more attractive to work in the pork sector of the food chain to the new generation of farmers and workers.

Anti-Steatotic Effects of Chlorella vulgaris, Nannochloropsis gaditana and Gracilaria vermiculophylla Algae Extracts in AML-12 Hepatocytes

Non-alcoholic fatty liver disease (NAFLD) is considered the most common chronic liver alteration whose prevalence is increasing in Western countries. Microalgae and macroalgae have attracted great interest due to the high content in bioactive compounds with beneficial effects on health. The aim of the present study is to assess the potential interest of extracts rich in proteins obtained from the microalgae Chlorella vulgaris and Nannochloropsis gaditana and the macroalga Gracilaria vermiculophylla in the prevention of lipid accumulation in AML-12 hepatocytes. Toxicity was not observed at any of the tested doses. Both microalgae and the macroalga were effective in preventing triglyceride accumulation, with Nannochloropsis gaditana being the most effective one. Although the three algae extracts were able to increase different catabolic pathways involved in triglyceride metabolism, the mechanisms underlying the anti-steatotic effect were different in each algae extract. In conclusion, the present study demonstrates that Chlorella vulgaris, Nannochloropsis gaditana and Gracilaria vermiculophylla extracts are able to partially prevent the accumulation of triglycerides induced by palmitic acid in cultured hepatocytes, a model used to mimic the steatosis induced in liver by dietary patterns rich in saturated fat.

Influence of the calcium and nutrient content of the prelay diet on egg production, egg quality, and tibiae mineralization of brown egg-laying hens from 16 to 63 wk of age

The influence of the Ca and nutrient content of the diet fed from 16 to 19 wk of age, on egg production, egg quality, and tibiae mineralization, was studied in brown egg-laying hens from 16 to 63 wk of age. The experimental design was completely randomized with 4 prelay diets organized as a 2 × 2 factorial with 2 levels of Ca (2.5 vs. 3.8%) and 2 standardized ileal digestible Lys (g/kg) to AMEn (Mcal/kg) ratios (DLys:ME; 2.84 vs. 3.13) as main effects. From 20 to 63 wk of age, all hens received a common diet with 2.75 Mcal AMEn/kg, 0.75% DLys, and 3.8% Ca. Each treatment was replicated 18 times and the experimental unit was a cage with 10 hens. Hen production and egg quality traits were measured by period (4 wk), feeding phase (prelay and lay), and cumulatively (16-63 wk of age) and tibiae mineralization was measured at 63 wk of age. During the prelay phase, an increase in Ca delayed egg production (P = 0.065), reduced feed intake (P < 0.05), and increased BW gain (P < 0.01) and percentage of shell of the egg (P < 0.05). An increase in the DLys:ME ratio increased feed intake (P < 0.01) and reduced egg size (P < 0.01). Nutrient content of the prelay diets did not affect hen production during the lay phase, except egg weight that increased (P < 0.05) in hens previously fed the low DLys:ME ratio. Eggshell quality (weight, percentage, strength, and thickness) in this phase was better (P < 0.05) in hens previously fed 3.8% Ca. Cumulatively (16-63 wk of age), hens fed the high Ca prelay diets had better shell quality but tibiae mineralization was not affected. In conclusion, an increase in Ca content of the prelay diet from 2.5 to 3.8% improved shell quality for the entire egg cycle without showing any negative effect on hen production.

Effect of beak trimming at hatch and the inclusion of oat hulls in the diet on growth performance, feed preference, exploratory pecking behavior, and gastrointestinal tract traits of brown-egg pullets from hatch to 15 weeks of age

The influence of infrared beak trimming at hatch (IRBT) and the inclusion of oat hulls (OH) in the diet on growth performance, feed preference, exploratory pecking behavior, and gastrointestinal tract (GIT) development, was studied in brown-egg pullets from 0 to 15 wk of age. The experimental design was completely randomized with 4 treatments arranged as a 2 × 2 factorial with IRBT (sham vs. treated) and OH inclusion (0 vs. 3%) as main effects. Each treatment was replicated 20 times and the experimental unit was a cage with 10 pullets. Feed intake (FI), BW gain, feed conversion ratio (FCR), energy intake (EI, kcal AMEn/d), and energy conversion ratio (ECR, kcal AMEn/g of BW gain) were determined by feeding period (0 to 6, 7 to 10, and 11 to 15 wk of age) and cumulatively. Particle size preference was measured at 7 wk and exploratory pecking behavior of the pullets and at 8 to 14 wk of age. From 0 to 6 wk of age, beak trimming decreased FI (P < 0.01) and increased pullet mortality (P < 0.001) but did not affect BW gain. From 0 to 15 wk of age, OH inclusion improved BW uniformity (P = 0.090) but impaired FCR (P < 0.05) without showing any effect on BW gain or ECR. Preference for coarse particles was greater for the sham than for the treated pullets. Beak trimming and OH feeding reduced (P < 0.05) the exploratory pecking behavior of the pullets from 8 to 12 wk of age but not thereafter. Oat hulls increased the relative weights of the full gizzard and intestines at all ages (P < 0.05). In summary, beak trimming did not affect pullet performance at 15 wk of age or GIT development at any age. Oat hulls improved GIT development at all ages but did not affect BW or ECR. Both beak treatment and OH inclusion affected particle size preference and reduced the exploratory pecking behavior of the birds.

Effect of Microalgae and Macroalgae Extracts on Non-Alcoholic Fatty Liver Disease

The present review aims to gather scientific evidence regarding the beneficial effects of microalgae and macroalgae extracts on non-alcoholic fatty liver disease (NAFLD). The described data show that both microalgae and macroalgae improved this alteration. The majority of the reported studies analysed the preventive effects because algae were administered to animals concurrent with the diet that induced NAFLD. The positive effects were demonstrated using a wide range of doses, from 7.5 to 300 mg/kg body weight/day or from 1 to 10% in the diet, and experimental periods ranged from 3 to 16 weeks. Two important limitations on the scientific knowledge available to date are that very few studies have researched the mechanisms of action underlying the preventive effects of microalgae on NAFLD and that, for the majority of the algae studied, a single paper has been reported. For these reasons, it is not possible to establish the best conditions in order to know the beneficial effects that these algae could bring. In this scenario, further studies are needed. Moreover, the beneficial effects of algae observed in rodent need to be confirmed in humans before we can start considering these products as new tools in the fight against fatty liver disease.

Effects of Pterostilbene on Diabetes, Liver Steatosis and Serum Lipids

Pterostilbene, a phenolic compound derived from resveratrol, possesses greater bioavailability than its parent compound due to the presence of two methoxyl groups. In this review, the beneficial effects of pterostilbene on diabetes, liver steatosis and dyslipidemia are summarized. Pterostilbene is a useful bioactive compound in preventing type 1 diabetes, insulin resistance and type 2 diabetes in animal models. Concerning type 1 diabetes, the main mechanisms described to justify the positive effects of this phenolic compound are increased liver glycogen content and hepatic glucokinase and phosphofructokinase activities, the recovery of pancreatic islet architecture, cytoprotection and a decrease in serum and pancreatic pro-inflammatory cytokines. As for type 2 diabetes, increased liver glucokinase and glucose-6-phosphatase and decreased fructose-1,6-biphosphatase activities are reported. When insulin resistance is induced by diets, a greater activation of insulin signaling cascade has been reported, increased cardiotrophin-1 levels and liver glucokinase and glucose- 6-phosphatase activities, and a decreased fructose-1,6-biphosphatase activity. Data concerning pterostilbene and liver steatosis are scarce so far, but the reduction in oxidative stress induced by pterostilbene may be involved since oxidative stress is related to the progression of steatosis to steatohepatitis. Finally, pterostilbene effectively reduces total cholesterol, LDL-cholesterol and serum triglyceride levels, while increases HDL-cholesterol in animal models of dyslipidemia.

Anti-Obesity Effects of Macroalgae

Macroalgae have attracted great interest for their potential applications in nutraceutical and pharmaceutical industries as source of bioactive medicinal products and food ingredients. This review gathers data from in vitro and in vivo studies addressing the anti-obesity effects of macroalgae. Great consensus exists in all reported in vitro studies concerning the reduction induced by seaweed extracts in the expression of transcriptional factors controlling adipogenesis. In animals, macroalgae reduced body fat accumulation and prevented other obesity features, such as dyslipidemia, insulin resistance and fatty liver. These effects are not due to food intake reduction, since few studies have reported such event. Indeed, the effects on metabolic pathways in target tissues/organs seem to play a more relevant role. Macroalgae can reduce de novo lipogenesis, limiting fatty acid availability for triglyceride synthesis in white adipose tissue. This effect has been observed in both cell cultures and adipose tissue from animals treated with macroalgae extracts. In addition, increased fatty acid oxidation and thermogenic capacity, as well as a shift towards healthier gut microbiota composition may contribute to the body fat-lowering effect of macroalgae. Studies in humans are needed to determine whether macroalgae can represent a feasible tool to prevent and/or manage overweight and obesity.

Influence of egg weight and inclusion of oat hulls in the diet on digestive tract traits and growth performance of brown pullets reared under stress conditions

We studied the influence of pre-hatch egg weight (EW) and the inclusion of oat hulls (OH) in the diet on gastrointestinal tract (GIT) traits and growth performance of pullets reared under stress conditions early in life. There were 14 treatments organized as a 7 × 2 factorial with 7 EW groups (47.0 to 54.0 g differing in 1 g between groups) and 2 inclusion levels of OH in the diet (0 vs. 3%). The pullets were reared under a series of stresses early in life (no access to feed for extended time post-hatching, reduced accessibility to feed and water at arrival to the farm, reduced ambient temperature at night, low light intensity, and hot-blade beak trimming at 18 D of age). Feed intake, BW gain, and FCR were measured by period (0 to 5, 5 to 10, and 10 to 16 wk of age) and cumulatively. Data were analyzed as a completely randomized design with EW and OH inclusion as main effects. In addition, EW effect was partitioned into linear and quadratic components. The stress conditions applied affected similarly the growth and GIT development of the pullets, independent of EW. An increase in EW increased BW at hatch and at 5 wk of age linearly (P < 0.05), but no effects were detected thereafter. Oat hulls inclusion increased ADFI and impaired FCR (P < 0.05) from 0 to 5 wk of age but did not affect energy efficiency at any age. At 5 wk of age, the relative weight (% BW) of the GIT decreased linearly (P < 0.05) with increases in EW and increased with OH inclusion (P < 0.05). Oat hulls inclusion increased the relative weight of the gizzard at all ages (P < 0.01). In conclusion, egg weight did not affect pullet growth from hatch to 16 wk of age. Independent of the initial BW of the pullets, OH inclusion improved gizzard development at all ages without affecting growth performance.

The influence of dietary conditions in the effects of resveratrol on hepatic steatosis

Non-alcoholic fatty liver disease (NAFLD) is considered the major cause for the development of chronic liver alterations.

The Diagnostic Laboratory Hub: A New Health Care System Reveals the Incidence and Mortality of Tuberculosis, Histoplasmosis, and Cryptococcosis of PWH in Guatemala

Background

A Diagnostic Laboratory Hub (DLH) was set up in Guatemala to provide opportunistic infection (OI) diagnosis for people with HIV (PWH).

Methods

Patients newly presenting for HIV, PWH not receiving antiretrovirals (ARVs) for >90 days but returned to care (Return/Restart), and PWH on ARVs with symptoms of OIs (ARV treatment) were prospectively included. Screening for tuberculosis, nontuberculous mycobacteria (NTM), histoplasmosis, and cryptococcosis was done. Samples were couriered to the DLH, and results were transmitted electronically. Demographic, diagnostic results, disease burden, treatment, and follow-up to 180 days were analyzed.

Results

In 2017, 1953 patients were included, 923 new HIV infections (an estimated 44% of all new HIV infections in Guatemala), 701 on ARV treatment, and 315 Return/Restart. Three hundred seventeen (16.2%) had an OI: 35.9% tuberculosis, 31.2% histoplasmosis, 18.6% cryptococcosis, 4.4% NTM, and 9.8% coinfections. Histoplasmosis was the most frequent AIDS-defining illness; 51.2% of new patients had <200 CD4 cells/mm³ with a 29.4% OI incidence; 14.3% of OIs in new HIV infections occurred with CD4 counts of 200-350 cells/mm³. OIs were the main risk factor for premature death for new HIV infections. At 180 days, patients with OIs and advanced HIV had 73-fold greater risk of death than those without advanced disease who were OI-free.

Conclusions

The DLH OI screening approach provides adequate diagnostic services and obtains relevant data. We propose a CD4 screening threshold of <350 cells/mm³. Mortality remains high, and improved interventions are required, including expansion of the DLH and access to antifungal drugs, especially liposomal amphotericin B and flucytosine.

Pterostilbene Reduces Liver Steatosis and Modifies Hepatic Fatty Acid Profile in Obese Rats

Excessive fat accumulation within the liver is known as “simple hepatic steatosis”, which is the most benign form of non-alcoholic fatty liver disease (NAFLD). The aim of the present study was to determine whether pterostilbene improves this hepatic alteration in Zucker (fa/fa) rats. Animals were distributed in two experimental groups (n = 10) and fed a standard laboratory diet. Rats in the pterostilbene group were given a dose of 30 mg/kg body weight/d for six weeks. After sacrifice, serum glucose, transaminase, and insulin concentrations were quantified and the liver triacylglycerol content and fatty acid profile was analyzed. Different pathways of triacylglycerol metabolism in liver were studied, including fatty acid synthesis and oxidation, triglyceride assembly, fatty acid uptake, and glucose uptake. With pterostilbene administration, a reduction in insulin concentrations (consequently in the Homeostatic Model Assessment for Insulin Resistance (HOMA-IR)) and hepatic triacylglycerol content were observed. No effects were observed in pterostilbene-treated rats in the activity of de novo lipogenesis enzymes. An improvement in the fatty acid profile was observed in pterostilbene-treated rats. In conclusion, pterostilbene is a useful molecule to reduce liver steatosis. Its delipidating effect is due, at least in part, to reduced fatty acid availability and triacylglycerol synthesis, as well as to an increased very low-density lipoprotein assembly and fatty acid oxidation.

Effect of Wakame and Carob Pod Snacks on Non-Alcoholic Fatty Liver Disease

Snacks combining different functional ingredients could represent a useful therapeutic strategy against NAFLD. The present study aimed to analyze the effect of two snack formulations based on carob and wakame flour in the treatment for NAFLD in rats. For this purpose, metabolic syndrome was induced in 50 adult rats by a high-fat high-fructose diet over eight weeks. After this period, rats were fed either normal calorie diets supplemented or not with snack A (1/50 wakame/carob pod) and snack B (1/5 wakame/carob pod) for four additional weeks. After sacrifice, liver composition and serum parameters were analyzed. Different pathways of triacylglycerol metabolism in liver were studied including fatty acid oxidation, fatty acid synthesis, triglyceride assembly and release, fatty acid uptake and glucose uptake. Oxidative stress was also measured. Snack treatment, and mainly B snack, reduced liver triacylglycerol levels by increasing fat oxidation. Moreover, this snack reduced oxidative stress. Therefore, this snack formulation could represent an interesting tool useful for fatty liver treatment.

The Dietary Antioxidant Piceatannol Inhibits Adipogenesis of Human Adipose Mesenchymal Stem Cells and Limits Glucose Transport and Lipogenic Activities in Adipocytes

Phenolic compounds are among the most investigated herbal remedies, as is especially the case for resveratrol. Many reports have shown its anti-aging properties and the ability to reduce obesity and diabetes induced by high-fat diet in mice. However, such beneficial effects hardly translate from animal models to humans. The scientific community has therefore tested whether other plant phenolic compounds may surpass the effects of resveratrol. In this regard, it has been reported that piceatannol reproduces in rodents the anti-obesity actions of its parent polyphenol. However, the capacity of piceatannol to inhibit adipocyte differentiation in humans has not been characterized so far. Here, we investigated whether piceatannol was antiadipogenic and antilipogenic in human preadipocytes. Human mesenchymal stem cells (hMSC), isolated from adipose tissues of lean and obese individuals, were differentiated into mature adipocytes with or without piceatannol, and their functions were explored. Fifty µM of piceatannol deeply limited synthesis/accumulation of lipids in both murine and hMSC-derived adipocytes. Interestingly, this phenomenon occurred irrespective of being added at the earlier or later stages of adipocyte differentiation. Moreover, piceatannol lowered glucose transport into adipocytes and decreased the expression of key elements of the lipogenic pathway (PPARγ, FAS, and GLUT4). Thus, the confirmation of the antiadipogenic properties of piceatanol in vitro warrants the realization of clinical studies for the application of this compound in the treatment of the metabolic complications associated with obesity.

Involvement of autophagy in the beneficial effects of resveratrol in hepatic steatosis treatment. A comparison with energy restriction

Involvement of autophagy in the liver delipidating effects of resveratrol and energy restriction.

Resveratrol-Induced Effects on Body Fat Differ Depending on Feeding Conditions

Science constantly seeks to identify new molecules that could be used as dietary functional ingredients in the fight against obesity and its co-morbidities. Among them, polyphenols represent a group of molecules of increasing interest. One of the most widely studied polyphenols is resveratrol (trans-3,4',5-trihydroxystilbene), which has been proposed as an "energy restriction mimetic" because it can exert energy restriction-like effects. The aim of this review is to analyze the effects of resveratrol on obesity under different feeding conditions, such as overfeeding, normal feeding, and energy restriction, in animals and humans. The vast majority of the studies reported have addressed the administration of resveratrol to animals alongside an obesogenic diet. Under these experimental conditions usually a decreased body weight amount was found. To date, studies that focus on the effects of resveratrol under normal feeding or energy restriction conditions in animals and humans are scarcer. In these studies no changes in body fat were reported. After analyzing the results obtained under overfeeding, normal feeding, and energy restriction conditions, it can be stated that resveratrol is useful in reducing body fat accumulation, and thus preventing obesity. Nevertheless, for ethical reasons, these results have been obtained in animals. By contrast, there are no evidences showing the usefulness of this phenolic compound in reducing previously accumulated body fat. Consequently, as of yet, there is not scientific support for proposing resveratrol as a new anti-obesity treatment tool.

Lack of Additive Effects of Resveratrol and Energy Restriction in the Treatment of Hepatic Steatosis in Rats

The aims of the present study were to analyze the effect of resveratrol on liver steatosis in obese rats, to compare the effects induced by resveratrol and energy restriction and to research potential additive effects. Rats were initially fed a high-fat high-sucrose diet for six weeks and then allocated in four experimental groups fed a standard diet: a control group, a resveratrol-treated group, an energy restricted group and a group submitted to energy restriction and treated with resveratrol. We measured liver triacylglycerols, transaminases, FAS, MTP, CPT1a, CS, COX, SDH and ATP synthase activities, FATP2/FATP5, DGAT2, PPARα, SIRT1, UCP2 protein expressions, ACC and AMPK phosphorylation and PGC1α deacetylation. Resveratrol reduced triacylglycerols compared with the controls, although this reduction was lower than that induced by energy restriction. The mechanisms of action were different. Both decreased protein expression of fatty acid transporters, thus suggesting reduced fatty acid uptake from blood stream and liver triacylglycerol delivery, but only energy restriction reduced the assembly. These results show that resveratrol is useful for liver steatosis treatment within a balanced diet, although its effectiveness is lower than that of energy restriction. However, resveratrol is unable to increase the reduction in triacylglycerol content induced by energy restriction.

Comparative effects of energy restriction and resveratrol intake on glycemic control improvement

Resveratrol (RSV) has been proposed as an energy restriction mimetic. This study aimed to compare the effects of RSV and energy restriction on insulin resistance induced by an obesogenic diet. Any additive effect of both treatments was also analyzed. Rats were fed a high-fat high-sucrose diet for 6 weeks. They were then distributed in four experimental groups which were either fed a standard control diet (C), or treated with RSV (30 mg/kg/d), or submitted to energy restriction (R, 15%), or treated with RSV and submitted to energy restriction (RR). A glucose tolerance test was performed, and serum glucose, insulin, fructosamine, adiponectin, and leptin concentrations determined. Muscle triacylglycerol content and protein expression of insulin receptor (IRβ), protein kinase B (Akt), Akt substrate of 160 kDa (AS160) and glucose transporter 4 (GLUT-4) were measured. In RSV rats, fructosamine concentrations were reduced, HOMA-IR remained unchanged, but glucose tolerance was improved, without changes in phosphorylation of IRβ, Akt, and AS160 or in GLUT-4 protein expression. Rats under energy restriction showed an improvement in all the markers related to glycemic control, as well as increased phosphorylation of AS160 and protein expression of GLUT-4. In rats from RR group the results were similar to R group, with the exception of IRβ and Akt phosphorylation, which were increased. In conclusion, mild energy restriction is more efficient than intake of RSV within a standard balanced diet, and acts by means of a different mechanism from that of RSV. No additive effects between RSV and energy restriction were observed. © 2017 BioFactors, 43(3):371-378, 2017.

Effects of pterostilbene in brown adipose tissue from obese rats

In recent years, much attention has been paid by the scientific community to phenolic compounds as active biomolecules naturally present in foods. Pterostilbene is a resveratrol dimethylether derivative which shows higher bioavailability. The aim of the present study was to analyze the effect of pterostilbene on brown adipose tissue thermogenic markers in a model of genetic obesity, which shows reduced thermogenesis. The experiment was conducted with 30 Zucker (fa/fa) rats that were distributed in three experimental groups: control and two groups orally administered with pterostilbene at 15 and 30 mg/kg body weight/day for 6 weeks. Gene expression of uncoupling protein 1 (Ucp1), peroxisome proliferator-activated receptor γ co-activator 1 α (Pgc-1α), carnitine palmitoyl transferase 1b (Cpt1b), peroxisome proliferator-activated receptor α (Pparα), nuclear respiratory factor 1 (Nfr1), and cyclooxygenase-2 (Cox-2); protein expression of PPARα, PGC-1α, p38 mitogen-activated protein kinase (p38 MAPK), UCP1 and glucose transporter (GLUT4); and enzyme activity of CPT 1b and citrate synthase (CS) were assessed in interscapular brown adipose tissue. With the exception of Pgc-1α expression, all these parameters were significantly increased by pterostilbene administration. These results show for the first time that pterostilbene increases thermogenic and oxidative capacity of brown adipose tissue in obese rats. Whether these effects effectively contribute to the antiobesity properties of these compound needs further research.

Involvement of miR-539-5p in the inhibition of de novo lipogenesis induced by resveratrol in white adipose tissue

Proposed miRNA mechanisms of action of resveratrol in triacylglycerol metabolism changes in adipose tissue.

MicroRNAs involved in the browning process of adipocytes

The present review focuses on the role of miRNAs in the control of white adipose tissue browning, a process which describes the recruitment of adipocytes showing features of brown adipocytes in white adipose tissue. MicroRNAs (miRNAs) are a class of short non-coding RNAs (19-22 nucleotides) involved in gene regulation. Although the main effect of miRNAs is the inhibition of the translational machinery, thereby preventing the production of the protein product, the activation of protein translation has also been described in the literature. In addition to modifying translation, miRNAs binding to its target mRNAs also trigger the recruitment and association of mRNA decay factors, leading to mRNA destabilization, degradation, and thus to the decrease in expression levels. Although a great number of miRNAs have been reported to potentially regulate genes that play important roles in the browning process, only a reduced number of studies have demonstrated experimentally an effect on this process associated to changes in miRNA expressions, so far. These studies have shown, by using either primary adipocyte cultures or experimental models of mice (KO mice, mice overexpressing a specific miRNA), that miR-196a, miR-26, and miR-30 are needed for browning process development. By contrast, miR-155, miR-133, miR-27b, and miR-34 act as negative regulators of this process [corrected]. Further studies are needed to fully describe the miRNA network-involved white adipose tissue browning regulation.

Potential renoprotective effects of piceatannol in ameliorating the early-stage nephropathy associated with obesity in obese Zucker rats

Obesity-associated nephropathy is considered to be a leading cause of end-stage renal disease. Resveratrol supplementation represents a promising therapy to attenuate kidney injury, but the poor solubility and limited bioavailability of this polyphenol limits its use in dietary intervention. Piceatannol, a resveratrol analogue, has been suggested as a better option. In this study, we aimed to provide evidence of a preventive action of piceatannol in very early stages of obesity-associated nephropathy. Thirty obese Zucker rats were divided into three experimental groups: one control and two groups orally treated for 6 weeks with 15 and 45 mg piceatannol/kg body weight/day. Enzyme-linked immunosorbent assays (ELISA) were used to determine renal and urinary kidney injury molecule-1 (Kim-1), renal fibrosis markers (transforming growth factor β1 and fibronectin) and renal sirtuin-1 protein. Oxidative stress was assessed in the kidney by measuring lipid peroxidation and nitrosative stress (thiobarbituric acid reactive substrates and 3-nitrotyrosine levels, respectively) together with the activity of the antioxidant enzyme superoxide dismutase. Renal fatty acids profile analysis was performed by thin-layer and gas chromatography. Piceatannol-treated rats displayed lower levels of urinary and renal Kim-1. Renal fibrosis biomarkers and lipid peroxidation exhibited a tendency to decrease in the piceatannol-treated groups. Piceatannol treatment did not modify superoxide dismutase activity or sirtuin-1 protein levels, while it seemed to increase the levels of polyunsaturated and omega-6 polyunsaturated fatty acids in the kidneys. Our findings suggest a mild renoprotective effect of piceatannol in obese Zucker rats and the need of intervention at early stages of renal damage.

Genetic relationships among American donkey populations: insights into the process of colonization

This study presents the first insights into the genetic diversity and structure of the American donkey metapopulation. The primary objectives were to detect the main structural features underlying variability among American donkey populations, identify boundaries between differentiated gene pools, and draw the main colonization pathways since the introduction of donkeys into America in the 15th century. A panel of 14 microsatellite markers was applied for genotyping 350 American donkeys from 13 countries. The genetic structure of this metapopulation was analysed using descriptive statistics and Bayesian model-based methods. These populations were then compared to a database containing information on 476 individuals from 11 European breeds to identify the most likely ancestral donor populations. Results showed the presence of two distinct genetic pools, with confluence of the two in Colombia. The southern pool showed a unique genetic signature subsequent to an older founder event, but lacked any significant influence of modern gene flow from Europe. The northern pool, conversely, may have retained more ancestral polymorphisms and/or have experienced modern gene flow from Spanish breeds. The Andalusian and, to a lesser extent, the Catalan breeds have left a more pronounced footprint in some of the American donkey populations analysed.

Potential application of non-flavonoid phenolics in diabetes: antiinflammatory effects

Polyphenols are members of a very large family of plant-derived compounds that may have beneficial effects on human health, and thus their study has become an increasingly important area of human nutrition research. Considering that it is increasingly accepted that chronic sub-acute inflammation plays an important role in the development of insulin resistance and of diabetes in animals and in humans, the aim of the present review is to compile information concerning the anti-inflammatory effects of non-flavonoid polyphenols on diabetes prevention and/or treatment. Most of these studies have been carried out with different cultured cells and using animal models displaying different types of diabetes, such as diabetes induced by streptozotocin or streptozotocin-nicotinamide, genetic diabetes or diabetes induced by high-fat feeding. In general terms, non-flavonoid polyphenols reduce the production of inflammatory mediators, such as IL-1β, IL-8, MCP-1, COX-2 or iNOS in these animal models of diabetes. This effect is accompanied in the vast majority of these studies by improved insulin action. In addition, some of the non-flavonoid polyphenols are also able to ameliorate or prevent several pathological alterations associated with the development of diabetes, such as nephropathy, cardiopathy or retinopathy. Very little information has been reported with regard to human studies to date. Thus, new studies are needed to confirm if the beneficial effects observed in preclinical studies can apply to human beings.

Liver delipidating effect of a combination of resveratrol and quercetin in rats fed an obesogenic diet

Liver steatosis is characterized by an abnormal accumulation of triacylglycerols in this organ. This metabolic disorder is closely associated with obesity. In the present study, we aimed to analyse the effect of a combination of resveratrol and quercetin on liver steatosis in an animal model of dietetic obesity, and to compare it with one induced by the administration of each polyphenol separately. Rats were divided into four dietary groups of nine animals each and fed a high-fat, high-sucrose diet: an untreated control group and three groups treated either with resveratrol (RSV; 15 mg/kg/day), with quercetin (Q; 30 mg/kg/day), or with both (RSV + Q; 15 mg resveratrol/kg/day and 30 mg quercetin/kg/day) for 6 weeks. Liver weight and triacylglycerol content decreased only in the RSV + Q group. A significant reduction in acetyl-CoA carboxylase activity was observed in RSV and RSV + Q groups, without changes in fatty acid synthase activity. A significant increase in carnitine palmitoyltransferase-1a activity was observed only in rats treated with the combination of resveratrol and quercetin, suggesting increased fatty acid oxidation. Citrate synthase, a marker of mitochondrial density, remained unchanged in all groups. No significant changes were observed in the expression of peroxisome proliferator-activated receptor α (PPARα), nuclear respiratory factor 1 (NRF-1) and transcription factor A mitochondrial (TFAM). In conclusion, resveratrol and quercetin together, combining two doses which were shown to be ineffective singly, is an interesting tool to prevent liver steatosis associated with high-fat high-sucrose feeding. The delipidating effect seems to be mediated by increased fatty acid oxidation not associated with increased mitochondriogenesis, and by reduced de novo lipogenesis.

Pterostilbene improves glycaemic control in rats fed an obesogenic diet: involvement of skeletal muscle and liver

This study aims to determine whether pterostilbene improved glycaemic control in rats showing insulin resistance induced by an obesogenic diet.

Resveratrol: anti-obesity mechanisms of action

Resveratrol is a non-flavonoid polyphenol which belongs to the stilbenes group and is produced naturally in several plants in response to injury or fungal attack. Resveratrol has been recently reported as preventing obesity. The present review aims to compile the evidence concerning the potential mechanisms of action which underlie the anti-obesity effects of resveratrol, obtained either in cultured cells lines and animal models. Published studies demonstrate that resveratrol has an anti-adipogenic effect. A good consensus concerning the involvement of a down-regulation of C/EBPα and PPARγ in this effect has been reached. Also, in vitro studies have demonstrated that resveratrol can increase apoptosis in mature adipocytes. Furthermore, different metabolic pathways involved in triacylglycerol metabolism in white adipose tissue have been shown to be targets for resveratrol. Both the inhibition of de novo lipogenesis and adipose tissue fatty acid uptake mediated by lipoprotein lipase play a role in explaining the reduction in body fat which resveratrol induces. As far as lipolysis is concerned, although this compound per se seems to be unable to induce lipolysis, it increases lipid mobilization stimulated by β-adrenergic agents. The increase in brown adipose tissue thermogenesis, and consequently the associated energy dissipation, can contribute to explaining the body-fat lowering effect of resveratrol. In addition to its effects on adipose tissue, resveratrol can also acts on other organs and tissues. Thus, it increases mitochondriogenesis and consequently fatty acid oxidation in skeletal muscle and liver. This effect can also contribute to the body-fat lowering effect of this molecule.

Novel equation to determine the hepatic triglyceride concentration in humans by MRI: diagnosis and monitoring of NAFLD in obese patients before and after bariatric surgery

BACKGROUND

Non-alcoholic fatty liver disease (NAFLD) is caused by abnormal accumulation of lipids within liver cells. Its prevalence is increasing in developed countries in association with obesity, and it represents a risk factor for non-alcoholic steatohepatitis (NASH), cirrhosis and hepatocellular carcinoma. Since NAFLD is usually asymptomatic at diagnosis, new non-invasive approaches are needed to determine the hepatic lipid content in terms of diagnosis, treatment and control of disease progression. Here, we investigated the potential of magnetic resonance imaging (MRI) to quantitate and monitor the hepatic triglyceride concentration in humans.

METHODS

A prospective study of diagnostic accuracy was conducted among 129 consecutive adult patients (97 obesity and 32 non-obese) to compare multi-echo MRI fat fraction, grade of steatosis estimated by histopathology, and biochemical measurement of hepatic triglyceride concentration (that is, Folch value).

RESULTS

MRI fat fraction positively correlates with the grade of steatosis estimated on a 0 to 3 scale by histopathology. However, this correlation value was stronger when MRI fat fraction was linked to the Folch value, resulting in a novel equation to predict the hepatic triglyceride concentration (mg of triglycerides/g of liver tissue = 5.082 + (432.104 * multi-echo MRI fat fraction)). Validation of this formula in 31 additional patients (24 obese and 7 controls) resulted in robust correlation between the measured and estimated Folch values. Multivariate analysis showed that none of the variables investigated improves the Folch prediction capacity of the equation. Obese patients show increased steatosis compared to controls using MRI fat fraction and Folch value. Bariatric surgery improved MRI fat fraction values and the Folch value estimated in obese patients one year after surgery.

CONCLUSIONS

Multi-echo MRI is an accurate approach to determine the hepatic lipid concentration by using our novel equation, representing an economic non-invasive method to diagnose and monitor steatosis in humans.

Pterostilbene, a dimethyl ether derivative of resveratrol, reduces fat accumulation in rats fed an obesogenic diet

The current study aimed to demonstrate the effects of pterostilbene in rats fed an obesogenic diet. For this purpose, pterostilbene was administered at doses of 15 mg/kg body weight/day (PT15 group) or 30 mg/kg body weight/day (PT30 group) for 6 weeks. Pterostilbene reduced adipose tissue mass -15.1% (PT15) and -22.9% (PT30). In this tissue, it decreased malic enzyme (-39.4 and -49.5% for PT15 and PT30 groups, respectively) and fatty acid synthase (-45 and -53.4% for PT15 and PT30) activities. Acetyl-CoA carboxylase activity was reduced and AMPK activity was increased only in the PT30 group. In the liver, pterostilbene (PT30) reduced malic enzyme (-29.5%) and glucose-6-P dehydrogenase (-43.2%) activities and increased carnitine palmitoyltransferase-1a (37.5%) and acyl-coenzyme A oxidase (42.5%) activities. This increased oxidative capacity was not associated with increased mitochondriogenesis. Among biochemical serum parameters, only insulin was modified by pterostilbene (-31.6%) in the PT15 group. The amounts of pterostilbene in serum and tissues from rats in the PT30 group were in not all cases 2-fold greater than those found in the PT15 group. In conclusion, pterostilbene shows antiobesity properties due, at least in part, to reduced lipogenesis in adipose tissue and increased fatty acid oxidation in liver.

Effects of resveratrol and other polyphenols in hepatic steatosis

Non-alcoholic fatty liver disease covers a wide spectrum of liver pathologies which range from simple steatosis to non-alcoholic steatohepatitis. Polyphenols are members of a very large family of plant-derived compounds that can have beneficial effects on human health, and thus their study has become an increasingly important area of human nutrition research. The aim of the present review is to compile published data concerning the effects of both isolated polyphenols as well as polyphenol extracts, on hepatocyte and liver fat accumulation under different steatosis-inducing conditions. The results reported clearly show that this group of biomolecules is able to reduce fat accumulation, but further studies are needed to establish the optimal dose and treatment period length. With regard to the potential mechanisms of action, there is a good consensus. The anti-lipidogenic effect of polyphenols is mainly due to reduced fatty acid and triacylglycerol synthesis, increased in fatty acid oxidation, and reduced of oxidative stress and inflammation. As a general conclusion, it can be stated that polyphenols are biomolecules which produce hepatoprotective effects. To date, these beneficial effects have been demonstrated in cultured cells and animal models. Thus, studies performed in humans are needed before these molecules can be considered as truly useful tools in the prevention of liver steatosis.

Changes in thigh muscle volume predict bone mineral density response to lifestyle therapy in frail, obese older adults

We studied the relationships among strength, muscle mass, and bone mineral density (BMD) with lifestyle change. Lifestyle therapy consisted of exercise, diet, and diet plus exercise. Diet was by caloric restriction to induce and maintain a weight loss of 10 % from baseline body weight. Exercise attenuated weight loss-induced muscle and bone losses. Exercise improved strength despite muscle loss in patients on diet and exercise. Changes in strength did not correlate with changes in BMD. However, changes in thigh muscle volume correlated with, and predicted changes in hip BMD.

INTRODUCTION

Losses of hip BMD and lean body mass are major complications of lifestyle therapy in frail, obese older adults; however, the contribution of mechanical strain loss from muscle loss is poorly defined. We determined the effect of changes in thigh muscle volume and muscle strength on BMD in frail, obese older adults undergoing lifestyle therapy aimed at intentional weight loss with or without exercise.

METHODS

One hundred seven obese older adults were randomized to control, diet, exercise, and diet-exercise groups for 1 year. Thigh muscle volume was measured by magnetic resonance imaging, BMD by DXA, knee strength by dynamometry, total strength by one-repetition maximum (1-RM), and bone markers by immunoassay.

RESULTS

Thigh muscle volume decreased in the diet group (-6.2 ± 4.8 %) and increased in the exercise group (2.7 ± 3.1 %), while it was not significantly different from the control in the diet-exercise group. Changes in hip BMD followed similar pattern as those in thigh muscle volume. Knee extension and flexion increased in the exercise group (23 ± 20 %; 25 ± 19 %) and diet-exercise group (20 ± 19 %; 20.6 ± 27 %) but were unchanged in the control and diet groups. Changes in thigh muscle volume correlated with changes in hip BMD (r = 0.55, P = <0.001) and were an independent predictor of changes in hip BMD (β = 0.12, P = 0.03) in the multiple regression analyses after accounting for demographic factors and changes in weight and physical activity. There were no correlations between BMD changes and knee strength, 1-RM, and sclerostin changes.

CONCLUSIONS

Changes in thigh muscle volume predict hip BMD changes in obese older patients undergoing lifestyle therapy. The effect of exercise in attenuating thigh muscle loss when added to diet may in part account for the reduction in weight loss-induced bone loss in the diet-exercise group.

Quercetin can reduce insulin resistance without decreasing adipose tissue and skeletal muscle fat accumulation

Quercetin exhibits a wide range of biological functions. The first aim of the present work was to analyze the effects of quercetin on fat accumulation in adipose tissue and glycemic control in rats. Any potential involvement of muscle fatty acid oxidation in its effect on glycemic control was also assessed. Animals were fed a high-fat high-sucrose diet either supplemented with quercetin (30 mg/kg body weight/day), or not supplemented, for 6 weeks. One week before killing, a glucose tolerance test was carried out. Muscle triacylglycerol content, serum glucose, insulin, fructosamine and free fatty acids were measured, and homeostatic model assessment for insulin resistance (HOMA-IR) was calculated. The activities of lipogenic enzymes and lipoprotein lipase in adipose tissue, carnitine palmitoyl transferase-1b (CPT-1b) and citrate synthase in skeletal muscle, and the expression of several genes, ACO, CD36, CPT-1b, PPAR-α, PGC-1α, UCP3, TFAM and COX-2 in skeletal muscle were analyzed. Quercetin caused no significant reduction in body weight or adipose tissue sizes. However, fructosamine, basal glucose and insulin, and consequently HOMA-IR, were significantly reduced by quercetin. No changes were observed in the activity of lipogenic enzymes and lipoprotein lipase. Muscle triacylglycerol content was similar in both experimental groups. The expression of ACO, CD36, CPT-1b, PPAR-α, PGC-1α, UCP3, TFAM and COX-2 remained unchanged. It can be concluded that quercetin is more effective as an anti-diabetic than as an anti-obesity biomolecule. The improvement in insulin resistance induced by this flavonoid is not mediated by a delipidating effect in skeletal muscle.

Impact of polyphenols and polyphenol-rich dietary sources on gut microbiota composition

Gut microbiota plays a key role in host physiology and metabolism. Indeed, the relevance of a well-balanced gut microbiota composition to an individual's health status is essential for the person's well-being. Currently, investigations are focused on analyzing the effects of pre- and probiotics as new therapeutic tools to counteract the disruption of intestinal bacterial balance occurring in several diseases. Polyphenols exert a wide range of beneficial health effects. However, although specific attention has been paid in recent years to the function of this "biological entity" in the metabolism of polyphenols, less is known about the modulatory capacity of these bioactive compounds on gut microbiota composition. This review provides an overview of the latest investigations carried out with pure polyphenols, extracts rich in polyphenols, and polyphenol-rich dietary sources (such as cocoa, tea, wine, soy products, and fruits) and critically discusses the consequences to gut microbiota composition which are produced.

The combination of resveratrol and conjugated linoleic acid attenuates the individual effects of these molecules on triacylglycerol metabolism in adipose tissue

PURPOSE

The combination of resveratrol + conjugated linoleic acid (RSV + CLA) did not show the body fat-lowering effect exhibited by these molecules when administered separately. This study aimed to find metabolic explanations for this situation in an experimental model of diet-induced obesity.

METHODS

Thirty-six male Wistar rats were divided into four groups: rats treated with saline (control), resveratrol (RSV), conjugated linoleic acid (CLA) and a combination of these molecules (RSV + CLA).

RESULTS

Rats treated with RSV + CLA did not show the reduction in heparin-releasable lipoprotein lipase (HR-LPL) and fatty acid synthase activities observed in RSV group or the increased HSL expression found in RSV and CLA groups. These animals showed reduced sirtuin 1 expression and CLA isomer amounts in adipose tissue. Finally, intracellular Ca(2+) concentration was increased.

CONCLUSION

The attenuation of the effects induced in adipose tissue triacylglycerol metabolism by RSV and CLA separately, such as the decrease in lipogenesis and fatty acid uptake and the increase in lipolysis, contributes to explain the lack of body fat-lowering effect of the combination RSV + CLA.

Several statins increase body and liver fat accumulation in a model of metabolic syndrome

Statins are a family of drugs used in hypercholesterolemia. The aim of this study was to analyze the effect of statins on body and liver fat accumulation in obese Zucker rats. Seventy Zucker (fa/fa) rats were divided into seven groups. Rats from six statin groups were treated with pravastatin, simvastatin, atorvastatin, rosuvastatin, fluvastatin and lovastatin respectively, at a dose of 0.6 mg/kg body weight/day. After 6 weeks, liver and white adipose tissue from intra-abdominal and subcutaneous locations were dissected and weighed. Subcutaneous adipose tissue from rosuvastatin, atorvastatin, fluvastatin and lovastatin treated rats was significantly increased. Fatty acid synthase (FAS) activity was increased by the administration of fluvastatin and lovastatin, as was glucose-6-P dehydrogenase (G6PDH) by the administration of atorvastatin and lovastatin. No changes were observed in malic enzyme (ME) activity. Furthermore, heparin-releasable lipoprotein lipase (HR-LPL) was increased in all groups where the subcutaneous depot was increased, and total LPL increased only in rosuvastatin and fluvastatin-treated groups. With regard to liver, there were no changes in weight but the amount of triacylglycerols was increased in rosuvastatin group, as well as its liver damage was higher. In this group FAS and G6PDH activities were increased and no changes were observed in ME, acyl CoA oxidase (ACO) and carnitine palmitoyltransferase-1a (CPT-1a) activities. All statins, with the exception of simvastatin, worsen insulin resistance. These results show that statins have different effects on body fat accumulation. Moreover, rosuvastatin also shows a prosteatotic effect. These results should be taken into account for statin choice in prescription.

Effects of pomegranate seed oil on glucose and lipid metabolism-related organs in rats fed an obesogenic diet

Studies conducted in mice have revealed positive effects of punicic acid (PUA). The aim of this study was to analyze the effects of PUA on fat accumulation and glycemic control in rats fed an obesogenic diet. Rats were randomly divided into two groups: control group and PUA group (diet supplemented with 0.5% PUA). No changes were observed in adipose tissue weights. The glucose tolerance test showed that the glycemic value in the PUA group had decreased significantly at the final time (120 min) (-19.3%), as had fructosamine levels (-11.1%). However, homeostasis model assessment (HOMA-IR) showed that insulin resistance did not improve. No changes were observed in the liver, skeletal muscle composition, or peroxisome proliferator-activated receptors (PPARs) activation. Low levels (mg/g tissue) of PUA (0.04 ± 0.01 in both tissues) and higher levels of cis-9,trans-11 conjugated linoleic acid (0.31 ± 0.08 in liver, 0.52 ± 0.11 in muscle) were found. PUA supplementation induced hypoplasia (-16.1%) due to the antiproliferative effect on hepatocytes. In conclusion, dietary supplementation of 0.5% PUA did not lead to decreased fat accumulation in adipose tissue, liver, or skeletal muscle, or to improved glycemic control. The hypoplasia induced in liver is a negative effect that should be considered before proposing PUA as a functional ingredient.

Porcine colonization of the Americas: a 60k SNP story

The pig, Sus scrofa, is a foreign species to the American continent. Although pigs originally introduced in the Americas should be related to those from the Iberian Peninsula and Canary islands, the phylogeny of current creole pigs that now populate the continent is likely to be very complex. Because of the extreme climates that America harbors, these populations also provide a unique example of a fast evolutionary phenomenon of adaptation. Here, we provide a genome wide study of these issues by genotyping, with a 60k SNP chip, 206 village pigs sampled across 14 countries and 183 pigs from outgroup breeds that are potential founders of the American populations, including wild boar, Iberian, international and Chinese breeds. Results show that American village pigs are primarily of European ancestry, although the observed genetic landscape is that of a complex conglomerate. There was no correlation between genetic and geographical distances, neither continent wide nor when analyzing specific areas. Most populations showed a clear admixed structure where the Iberian pig was not necessarily the main component, illustrating how international breeds, but also Chinese pigs, have contributed to extant genetic composition of American village pigs. We also observe that many genes related to the cardiovascular system show an increased differentiation between altiplano and genetically related pigs living near sea level.

[Isolated non-compaction of the left ventricle]

Isolated non compaction of the left ventricle is a rare congenital cardiomyopathy linked to an arrest of normal myocardial embryogenesis. We report two cases of isolated non compaction of the left ventricle discovered by echocardiography in 2 males of 30 and 55 years. The first had progressively worsening cardiac insufficiency, the second was being followed for an unexplained cardiomyopathy. In both cases, the diagnosis was able to be confirmed by transthoracic echocardiography, supported by MRI data. Although present from birth, this condition can become apparent at various ages and is complicated by sudden death (principal cause of mortality), severe cardiac insufficiency, or thrombo-embolic accidents. The diagnosis of left ventricular non compaction should be considered when faced with unexplained cardiac insufficiency in the adult.

Effects of supplemental oxygen during activity in patients with advanced COPD without severe resting hypoxemia

STUDY OBJECTIVES

To assess oxygen desaturation during activities and to evaluate the short-term effects of supplemental O(2) use in patients with severe COPD who do not qualify for long-term O(2) therapy.

DESIGN

A double-blind, randomized, placebo-controlled trial.

SETTING

Outpatients from the pulmonary diseases division of a tertiary-care university hospital.

PATIENTS

Twenty patients with stable COPD with FEV(1)/FVC ratios of < 50%, FEV(1) levels < 55% of the predicted normal value, and PaO(2) levels of > 60 mm Hg when resting.

INTERVENTIONS

Patients were initially evaluated with pulmonary function tests, blood gas analysis, and Doppler echocardiography, and they underwent the following three 6-min walking tests (WTs) in a random sequence: basal WT (BWT); WT while breathing compressed air (CAWT); and WT while breathing O(2) (O(2)WT).

MEASUREMENTS AND RESULTS

The distance walked was recorded in meters. Dyspnea was measured by Borg scale measurement before and after the tests, and arterial oxygen saturation measured by pulse oximetry (SpO(2)) was continuously monitored. Results were analyzed by grouping patients in the following manner: desaturators (DSs) (ie, patients with a drop in SpO(2) of at least 5% and < 90% during the WT) vs nondesaturators (NDSs); and O(2) responders (ie, patients with an increase of at least 10% in the distance walked and/or a decrease of at least 3 points in Borg index score) vs nonresponders. During the BWT, 11 of 20 patients (55%) were defined as desaturators. During the O(2)WT, the SpO(2) remained at > 90% in every patient. The distance walked increased by 22% (p < 0.02), and dyspnea decreased 36% (p < 0.01) in DS patients. In NDS patients, O(2) administration reduced dyspnea by 47% (p < 0.001), but the distance walked did not improve. Responses were markedly different from one patient to another. No significant differences were noticed between the results of the BWT and CAWT in any of the groups. Thirteen O(2) responders did not differ from 7 nonresponders either in basal data or in desaturation measure during the BWT, except that all walking responders (five patients) were above the median of basal left ventricle performance.

CONCLUSIONS

Most of the studied COPD patients desaturated during the BWT. O(2) administration avoided desaturation and could increase the distance walked and reduce dyspnea, but these effects were not related to walking desaturation in individual cases. Improvements were not a placebo effect. The therapeutic role of O(2) during activities in some patients with severe COPD needs to be individually assessed.

The cytoskeletal/non-muscle isoform of alpha-actinin is phosphorylated on its actin-binding domain by the focal adhesion kinase

alpha-Actinin is tyrosine-phosphorylated in activated human platelets (Izaguirre, G., Aguirre, L., Ji, P., Aneskievich, B., and Haimovich, B. (1999) J. Biol. Chem. 274, 37012--37020). Analysis of platelet RNA by reverse transcription-polymerase chain reaction revealed that alpha-actinin expressed in platelets is identical to the cytoskeletal/non-muscle isoform. A construct of this isoform containing a His(6) tag at the amino terminus was generated. Robust tyrosine phosphorylation of the recombinant protein was detected in cells treated with the tyrosine phosphatase inhibitor vanadate. The tyrosine phosphorylation site was localized to the amino-terminal domain by proteolytic digestion. A recombinant alpha-actinin protein containing a Tyr --> Phe mutation at position 12 (Y12F) was no longer phosphorylated when expressed in vanadate-treated cells, indicating that tyrosine 12 is the site of phosphorylation. The wild type recombinant protein was not phosphorylated in cells lacking the focal adhesion kinase (FAK). Re-expression of FAK in these cells restored alpha-actinin phosphorylation. Purified wild type alpha-actinin, but not the Y12F mutant, was phosphorylated in vitro by wild type as well as a Phe-397 mutant of FAK. In contrast, no phosphorylation was detected in the presence of a kinase-dead FAK. Tyrosine phosphorylation reduced the amount of alpha-actinin that cosedimented with actin filaments. These results establish that alpha-actinin is a direct substrate for FAK and suggest that alpha-actinin mediates FAK-dependent signals that could impact the physical properties of the cytoskeleton.

Interleukin-10 inhibits intimal hyperplasia after angioplasty or stent implantation in hypercholesterolemic rabbits

BACKGROUND

Intimal hyperplasia after stent implantation is the main cause of in-stent restenosis. Activated monocytes play a key role in intimal growth. The anti-inflammatory cytokine interleukin-10 (IL-10) is a potent monocyte deactivator, endogenously produced in the atherosclerotic plaque. We tested the hypothesis that exogenous IL-10 may limit postangioplasty intimal hyperplasia after balloon angioplasty or stenting.

METHODS AND RESULTS

Hypercholesterolemic rabbits were treated with recombinant human IL-10 (rhuIL-10) for 3 days after balloon angioplasty or 28 days after stent implantation. High IL-10 serum levels and intense deactivation of circulating monocytic cells, assessed by inhibition of IL-1beta release by lipopolysaccharide-stimulated whole blood, were detected for at least 8 hours after rhuIL-10 intravenous injection (ELISA). Morphometric analyses, performed 28 days after injury, indicated that rhuIL-10 reduced intimal growth by approximately 50% after balloon angioplasty or stenting, resulting in more preserved lumen in stented arteries. Moreover, rhuIL-10 reduced macrophage infiltration by 67% and proliferative activity by 81% in the intima and the media. No toxic effect was detected except minor changes in blood cell count.

CONCLUSIONS

The anti-inflammatory cytokine rhuIL-10 reduces postinjury intimal hyperplasia. The potent attenuation of in-stent intimal growth by rhuIL-10 and its favorable toxicity profile suggest that rhuIL-10 may be useful in the prevention of in-stent restenosis.

Tyrosine phosphorylation of alpha-actinin in activated platelets

The integrin alpha(IIb)beta(3) mediates tyrosine phosphorylation of a 105-kDa protein (pp105) in activated platelets. We have partially purified a 105-kDa tyrosine-phosphorylated protein from platelets stimulated with phorbol 12-myristate 13-acetate and obtained the sequence of an internal 12-mer peptide derived from this protein. The sequence was identical to human alpha-actinin sequences deposited in the Swiss Protein Database. alpha-Actinin, a 105-kDa protein in platelets, was subsequently purified from activated platelets by four sequential chromatographic steps. Fractions were analyzed by Western blotting and probed with alpha-actinin and anti-phosphotyrosine antibodies. The distribution of alpha-actinin and pp105 overlapped throughout the purification. Furthermore, in the course of this purification, a 105-kDa tyrosine-phosphorylated protein was only detected in fractions that contained alpha-actinin. The purified alpha-actinin protein was immunoprecipitated with antibodies to phosphotyrosine in the absence but not in the presence of phenyl phosphate. alpha-Actinin resolved by two-dimensional gel electrophoresis of activated platelet lysates was recognized by the antibodies to phosphotyrosine, whereas pretreatment of the platelets with bisindolylmaleimide, a protein kinase C inhibitor that prevents tyrosine phosphorylation of pp105, inhibited the reactivity of the antibodies to phosphotyrosine with alpha-actinin. Taken together, these data demonstrate that a fraction of alpha-actinin is tyrosine-phosphorylated in activated platelets.

Flow cytometric study of mitochondrial dysfunction after AMPA receptor activation

The effect of AMPA-receptor stimulation on MMP and on the concentration of intracellular calcium ([Ca2+]i) was studied in dissociated CGC from rat pups, by flow cytometry. In the presence of cyclothiazide, AMPA induced a sodium-independent decrease in MMP up to 30.7+/-2.5%. This effect was antagonized by CNQX and NBQX. Mepacrine and dibucaine reversed the effect of AMPA on MMP, suggesting that it is mediated by a release of arachidonic acid. AMPA alone induced a slight (about 7%) increase in [Ca2+]i. In the presence of cyclothiazide, AMPA induced a concentration-dependent [Ca2+]i increase up to 29.10+/-2.10% that was not reversed by flunarizine. This increase was similar to that observed in a Na+-free medium, and was antagonized by CNQX and NBQX, but not by MK-801. Mitochondria play a key role in the modulation of [Ca2+]i since a significant [Ca2+]i increase was found in the presence of FCCP. On the other hand, the dantrolene-sensitive calcium pools do not participate in the [Ca2+]i increase induced by stimulation of AMPA receptors. It is concluded that when AMPA-receptor desensitization is blocked, a decrease in MMP and an increase in [Ca2+]i occurs, which could be additional events to potentiate neuronal cell death induced by glutamate.

U-83836E prevents kainic acid-induced neuronal damage

The effect of kainic acid (KA) on mitochondrial membrane potential (MMP) and reactive-oxygen species (ROS) production was studied in dissociated cerebellar granule cells from rat pups. KA induced a maximum increase of 361%+/-35% in ROS production. The lazaroid compound U-83836E (at concentrations ranging from 10(-9) to 5x10(-6) M) completely inhibited this increase, with an IC50 value of 3.02+/-1.08x10(-7) M. KA also decreased the mitochondrial membrane potential (MMP), with a maximum decrease of about 30%. Absence of Na+ in the incubation medium did not significantly alter the effect of KA on MMP. As expected, the AMPA/kainate receptor antagonist NBQX inhibited the effects of KA on MMP with an IC50 value of 1.1+/-0.8 microM. However, the lazaroid U-83836E, indomethacin, nor-dihydroguaiaretic acid and L-nitroarginine all failed to inhibit the KA-induced decrease in the MMP. Finally, to assess the neuroprotective effect of U-83836E on KA-induced neurotoxicity in vivo, the increase in the peripheral-type benzodiazepine receptor density in rat hippocampus was measured. Treatment with KA increased the Bmax to 1341+/-192 fmol mg(-1). When U-83836E was coadministered with KA, the Bmax was reduced to 765+/-122 fmol mg(-1), which was not significantly different from the Bmax obtained from untreated rats (Bmax: 518+/-33 fmol mg(-1)). We conclude that treatment with the lazaroid U-83836E might be a suitable therapeutic strategy in neurodegenerative disorders.