Metabolic profile analysis of zebrafish embryos

A growing goal in the field of metabolism is to determine the impact of genetics on different aspects of mitochondrial function. Understanding these relationships will help to understand the underlying etiology for a range of diseases linked with mitochondrial dysfunction, such as diabetes and obesity. Recent advances in instrumentation, has enabled the monitoring of distinct parameters of mitochondrial function in cell lines or tissue explants. Here we present a method for a rapid and sensitive analysis of mitochondrial function parameters in vivo during zebrafish embryonic development using the Seahorse bioscience XF 24 extracellular flux analyser. This protocol utilizes the Islet Capture microplates where a single embryo is placed in each well, allowing measurement of bioenergetics, including: (i) basal respiration; (ii) basal mitochondrial respiration (iii) mitochondrial respiration due to ATP turnover; (iv) mitochondrial uncoupled respiration or proton leak and (iv) maximum respiration. Using this approach embryonic zebrafish respiration parameters can be compared between wild type and genetically altered embryos (mutant, gene over-expression or gene knockdown) or those manipulated pharmacologically. It is anticipated that dissemination of this protocol will provide researchers with new tools to analyse the genetic basis of metabolic disorders in vivo in this relevant vertebrate animal model.

Metabolite profiling of biological extracts

Metabolite profiling, HPLC, LC-QTOF-MS, GC-MS. A workflow will be presented for comprehensive metabolomics using LC- and GC-MS. Metabolomics is an emerging field in the suite of ‘omic’ approaches for Systems Biology. The goal of metabolomics is to detect the presence of all small-molecules in a biological sample. This presents a significant challenge due to the chemical diversity and large concentration range of metabolites. Currently, there is no single method which enables the entire metabolome to be analysed, therefore a suite of analytical approaches are required to increase the coverage of detected metabolites. The routinely used techniques for metabolite profiling are LC- and GC-MS and NMR. Here we present complementary approaches using MS hyphenated to different chromatographic techniques. GC-MS represent the most robust standardised technique for high throughput metabolite profiling however there are still no standard LC-based methods for profiling. Polar compounds represent the most challenging aspect of LC-based metabolomics. A robust chromatographic technique for profiling polar compounds using HILIC chromatography and QTOF-MS will be presented as well as the complimentary reverse phase LC-MS method. The polar separation was carried out using a diamond hydride column. This unique stationary phase provides stable retention times and fast re-equilibration which contrasts to other forms of HILIC stationary phases. These LC-based methods will be compared to the well established GC-MS method as well as NMRbased profiling.

Independent and joint associations of TV viewing time and snack food consumption with the metabolic syndrome and its components; a cross-sectional study in Australian adults

Background:
Television (TV) viewing time is positively associated with the metabolic syndrome (MetS) in adults. However, the mechanisms through which TV viewing time is associated with MetS risk remain unclear. There is evidence that the consumption of energy-dense, nutrient poor snack foods increases during TV viewing time among adults, suggesting that these behaviors may jointly contribute towards MetS risk. While the association between TV viewing time and the MetS has previously been shown to be independent of adult’s overall dietary intake, the specific influence of snack food consumption on the relationship is yet to be investigated. The purpose of this study was to examine the independent and joint associations of daily TV viewing time and snack food consumption with the MetS and its components in a sample of Australian adults.

Methods:
Population-based, cross-sectional study of 3,110 women and 2,572 men (>35 years) without diabetes or cardiovascular disease. Participants were recruited between May 1999 and Dec 2000 in the six states and the Northern Territory of Australia. Participants were categorised according to self-reported TV viewing time (low: 0-2 hr/d; high: >2 hr/d) and/or consumption of snack foods (low: 0-3 serves/d; high: >3 serves/d). Multivariate odds ratios [95% CI] for the MetS and its components were estimated using gender-specific, forced entry logistic regression.

Results:
OR [95% CI] for the MetS was 3.59 [2.25, 5.74] (p≤0.001) in women and 1.45 [1.02, 3.45] (p = 0.04) in men who jointly reported high TV viewing time and high snack food consumption. Obesity, insulin resistance and hypertension (women only) were also jointly associated with high TV viewing time and high snack food consumption. Further adjustment for diet quality and central adiposity maintained the associations in women. High snack food consumption was also shown to be independently associated with MetS risk [OR: 1.94 (95% CI: 1.45, 2.60), p < 0.001] and hypertension [OR: 1.43 (95% CI: 1.01, 2.02), p = 0.05] in women only. For both men and women, high TV viewing time was independently associated with the MetS and its individual components (except hypertension).

Conclusion:
TV viewing time and snack food consumption are independently and jointly associated with the MetS and its components, particularly in women. In addition to physical activity, population strategies targeting MetS prevention should address high TV time and excessive snack food intake.

Caveolin-1 Is Necessary for Hepatic Oxidative Lipid Metabolism: Evidence for Crosstalk between Caveolin-1 and Bile Acid Signaling

Caveolae and caveolin-1 (CAV1) have been linked to several cellular functions. However, a model explaining their roles in mammalian tissues in vivo is lacking. Unbiased expression profiling in several tissues and cell types identified lipid metabolism as the main target affected by CAV1 deficiency. CAV1−/− mice exhibited impaired hepatic peroxisome proliferator-activated receptor α (PPARα)-dependent oxidative fatty acid metabolism and ketogenesis. Similar results were recapitulated in CAV1-deficient AML12 hepatocytes, suggesting at least a partial cell-autonomous role of hepatocyte CAV1 in metabolic adaptation to fasting. Finally, our experiments suggest that the hepatic phenotypes observed in CAV1−/− mice involve impaired PPARα ligand signaling and attenuated bile acid and FXRα signaling. These results demonstrate the significance of CAV1 in (1) hepatic lipid homeostasis and (2) nuclear hormone receptor (PPARα, FXRα, and SHP) and bile acid signaling.

Profiling the Australian high performance and sports science workforce

Australia is viewed as leader in the field of sports science, with Australian sports scientists highly sought after and respected worldwide. However, despite the important contribution of sports scientists to the development of professional sport in Australia, we know little about these sport professionals who play an important role in the development and success of athletes, teams and sport organisations.
This report provides a more formal understanding of the high performance and sports science workforce with the purpose of informing the policy development of Australia’s sport governing bodies and education providers to inform sport management practices that will enhance the support and development of current and future high performance managers and sports scientists. The data presented in this report provides valuable insight about the scope of the profession to enable further development of strategic plans for the industry.

Profiling phishing email based on clustering approach

In this paper, an approach for profiling email-born phishing activities is proposed. Profiling phishing activities are useful in determining the activity of an individual or a particular group of phishers. By generating profiles, phishing activities can be well understood and observed. Typically, work in the area of phishing is intended at detection of phishing emails, whereas we concentrate on profiling the phishing email. We formulate the profiling problem as a clustering problem using the various features in the phishing emails as feature vectors. Further, we generate profiles based on clustering predictions. These predictions are further utilized to generate complete profiles of these emails. The performance of the clustering algorithms at the earlier stage is crucial for the effectiveness of this model. We carried out an experimental evaluation to determine the performance of many classification algorithms by incorporating clustering approach in our model. Our proposed profiling email-born phishing algorithm (ProEP) demonstrates promising results with the RatioSize rules for selecting the optimal number of clusters.

Depression, anxiety and metabolic syndrome in farm men and women

This research found that Depression was associated with the development of metabolic syndrome, whilst both Depression and Anxiety are associated with the maintenance of metabolic syndrome in Farm men and women. Future interventions in metabolic syndrome should consider screening for and treating these psychological factors to improve health outcomes.

Tumor progression locus 2 (Tpl2) deficiency does not protect against obesity-induced metabolic disease

Obesity is associated with a state of chronic low grade inflammation that plays an important role in the development of insulin resistance. Tumor progression locus 2 (Tpl2) is a serine/threonine mitogen activated protein kinase kinase kinase (MAP3K) involved in regulating responses to specific inflammatory stimuli. Here we have used mice lacking Tpl2 to examine its role in obesity-associated insulin resistance. Wild type (wt) and tpl22/2 mice accumulated comparable amounts of fat and lean mass when fed either a standard chow diet or two different high fat (HF) diets containing either 42% or 59% of energy content derived from fat. No differences in glucose tolerance were observed between wt and tpl22/2 mice on any of these diets. Insulin tolerance was similar on both standard chow and 42% HF diets, but was slightly impaired in tpl22/2 mice fed the 59% HFD. While gene expression markers of macrophage recruitment and inflammation were increased in the white adipose tissue of HF fed mice compared with standard chow fed mice, no differences were observed between wt and tpl2 mice. Finally, a HF diet did not increase Tpl2 expression nor did it activate Extracellular Signal-Regulated Kinase 1/2 (ERK1/2), the MAPK downstream of Tpl2. These findings argue that Tpl2 does not play a non-redundant role in obesity associated metabolic dysfunction.

Rapid development of non-alcoholic steatohepatitis in Psammomys obesus (Israeli Sand Rat)

Background and AimsA major impediment to establishing new treatments for non-alcoholic steatohepatitis is the lack of suitable animal models that accurately mimic the biochemical and metabolic characteristics of the disease. The aim of this study was to explore a unique polygenic animal model of metabolic disease as a model of non-alcoholic steatohepatitis by determining the effects of 2% dietary cholesterol supplementation on metabolic and liver endpoints in Psammomys obesus (Israeli sand rat).MethodsP. obesus were provided ad libitum access to either a standard rodent diet (20% kcal/fat) or a standard rodent diet supplemented with 2% cholesterol (w/w) for 4 weeks. Histological sections of liver from animals on both diets were examined for key features of non-alcoholic steatohepatitis. The expression levels of key genes involved in hepatic lipid metabolism were measured by real-time PCR.ResultsP. obesus fed a cholesterol-supplemented diet exhibited profound hepatomegaly and steatosis, and higher plasma transaminase levels. Histological analysis identified extensive steatosis, inflammation, hepatocyte injury and fibrosis. Hepatic gene expression profiling revealed decreased expression of genes involved in delivery and uptake of lipids, and fatty acid and triglyceride synthesis, and increased expression of genes involved in very low density lipoprotein cholesterol synthesis, triglyceride and cholesterol export.ConclusionsP. obesus rapidly develop non-alcoholic steatohepatitis when fed a cholesterol-supplemented diet that appears to be histologically and mechanistically similar to patients.