mTORC2 sustains thermogenesis via Akt-induced glucose uptake and glycolysis in brown adipose tissue

Activation of non-shivering thermogenesis (NST) in brown adipose tissue (BAT) has been proposed as an anti-obesity treatment. Moreover, cold-induced glucose uptake could normalize blood glucose levels in insulin-resistant patients. It is therefore important to identify novel regulators of NST and cold-induced glucose uptake. Mammalian target of rapamycin complex 2 (mTORC2) mediates insulin-stimulated glucose uptake in metabolic tissues, but its role in NST is unknown. We show that mTORC2 is activated in brown adipocytes upon β-adrenergic stimulation. Furthermore, mice lacking mTORC2 specifically in adipose tissue (AdRiKO mice) are hypothermic, display increased sensitivity to cold, and show impaired cold-induced glucose uptake and glycolysis. Restoration of glucose uptake in BAT by overexpression of hexokinase II or activated Akt2 was sufficient to increase body temperature and improve cold tolerance in AdRiKO mice. Thus, mTORC2 in BAT mediates temperature homeostasis via regulation of cold-induced glucose uptake. Our findings demonstrate the importance of glucose metabolism in temperature regulation

High-Precision Measurement of the 19Ne Half-Life and Implications for Right-Handed Weak Currents

We report a precise determination of the 19Ne half-life to be $T_{1/2} = 17.262 \pm 0.007$ s. This result disagrees with the most recent precision measurements and is important for placing bounds on predicted right-handed interactions that are absent in the current Standard Model. We are able to identify and disentangle two competing systematic effects that influence the accuracy of such measurements. Our findings prompt a reassessment of results from previous high-precision lifetime measurements that used similar equipment and methods.Comment: 5 pages and 5 figures. Paper accepted for publication in Phys. Rev. Let

Single stage repair of a complex pathology: end stage ischaemic cardiomyopathy, ascending aortic aneurysm and thoracic coarctation

The not uncommon combination of ascending aortic pathology with late presenting coarctation is a difficult surgical challenge. The two stage approach is usually adopted. The necessity for cardiac transplantation adds to the complexity: a trans-sternal approach and single stage repair become mandatory

Absence of molecular mobility on nano-second time scales in amorphous ice phases

High-resolution neutron backscattering techniques are exploited to study the elastic and quasi-elastic response of the high-density amorphous (HDA), the low-density amorphous (LDA) and the crystalline ice Ic upon temperature changes. Within the temperature ranges of their structural stability (HDA at T > 80 K, LDA at T > 135 K, ice Ic at T < 200 K) the Debye-Waller factors and mean-square displacements characterise all states as harmonic solids. During the transformations HDA->LDA (T ~ 100 K), LDA->Ic (T ~ 150K) and the supposed glass transition with Tg ~ 135 K no relaxation processes can be detected on a time scale t < 4 ns. It can be concluded from coherent scattering measurements (D_2O) that LDA starts to recrystallise into ice Ic at T ~ 135 K, i.e. at the supposed Tg. In the framework of the Debye model of harmonic solids HDA reveals the highest Debye temperature among the studied ice phases, which is in full agreement with the lowest Debye level in the generalised density of states derived from time-of-flight neutron scattering experiments. The elastic results at low T indicate the presence of an excess of modes in HDA, which do not obey the Bose statistics

Two-neutron transfer reaction mechanisms in 12^{12}C(6^6He,4^{4}He)14^{14}C using a realistic three-body 6^{6}He model

The reaction mechanisms of the two-neutron transfer reaction $^{12}$C($^6$He,$^4$He) have been studied at 30 MeV at the TRIUMF ISAC-II facility using the SHARC charged-particle detector array. Optical potential parameters have been extracted from the analysis of the elastic scattering angular distribution. The new potential has been applied to the study of the transfer angular distribution to the 2$^+_2$ 8.32 MeV state in $^{14}$C, using a realistic 3-body $^6$He model and advanced shell model calculations for the carbon structure, allowing to calculate the relative contributions of the simultaneous and sequential two-neutron transfer. The reaction model provides a good description of the 30 MeV data set and shows that the simultaneous process is the dominant transfer mechanism. Sensitivity tests of optical potential parameters show that the final results can be considerably affected by the choice of optical potentials. A reanalysis of data measured previously at 18 MeV however, is not as well described by the same reaction model, suggesting that one needs to include higher order effects in the reaction mechanism.Comment: 9 pages, 9 figure

Genome-Wide Survey for Biologically Functional Pseudogenes

According to current estimates there exist about 20,000 pseudogenes in a mammalian genome. The vast majority of these are disabled and nonfunctional copies of protein-coding genes which, therefore, evolve neutrally. Recent findings that a Makorin1 pseudogene, residing on mouse Chromosome 5, is, indeed, in vivo vital and also evolutionarily preserved, encouraged us to conduct a genome-wide survey for other functional pseudogenes in human, mouse, and chimpanzee. We identify to our knowledge the first examples of conserved pseudogenes common to human and mouse, originating from one duplication predating the human–mouse species split and having evolved as pseudogenes since the species split. Functionality is one possible way to explain the apparently contradictory properties of such pseudogene pairs, i.e., high conservation and ancient origin. The hypothesis of functionality is tested by comparing expression evidence and synteny of the candidates with proper test sets. The tests suggest potential biological function. Our candidate set includes a small set of long-lived pseudogenes whose unknown potential function is retained since before the human–mouse species split, and also a larger group of primate-specific ones found from human–chimpanzee searches. Two processed sequences are notable, their conservation since the human–mouse split being as high as most protein-coding genes; one is derived from the protein Ataxin 7-like 3 (ATX7NL3), and one from the Spinocerebellar ataxia type 1 protein (ATX1). Our approach is comparative and can be applied to any pair of species. It is implemented by a semi-automated pipeline based on cross-species BLAST comparisons and maximum-likelihood phylogeny estimations. To separate pseudogenes from protein-coding genes, we use standard methods, utilizing in-frame disablements, as well as a probabilistic filter based on Ka/Ks ratios

Changes in Proteasome Structure and Function Caused by HAMLET in Tumor Cells

BACKGROUND: Proteasomes control the level of endogenous unfolded proteins by degrading them in the proteolytic core. Insufficient degradation due to altered protein structure or proteasome inhibition may trigger cell death. This study examined the proteasome response to HAMLET, a partially unfolded protein-lipid complex, which is internalized by tumor cells and triggers cell death. METHODOLOGY/PRINCIPAL FINDINGS: HAMLET bound directly to isolated 20S proteasomes in vitro and in tumor cells significant co-localization of HAMLET and 20S proteasomes was detected by confocal microscopy. This interaction was confirmed by co-immunoprecipitation from extracts of HAMLET-treated tumor cells. HAMLET resisted in vitro degradation by proteasomal enzymes and degradation by intact 20S proteasomes was slow compared to fatty acid-free, partially unfolded alpha-lactalbumin. After a brief activation, HAMLET inhibited proteasome activity in vitro and in parallel a change in proteasome structure occurred, with modifications of catalytic (beta1 and beta5) and structural subunits (alpha2, alpha3, alpha6 and beta3). Proteasome inhibition was confirmed in extracts from HAMLET-treated cells and there were indications of proteasome fragmentation in HAMLET-treated cells. CONCLUSIONS/SIGNIFICANCE: The results suggest that internalized HAMLET is targeted to 20S proteasomes, that the complex resists degradation, inhibits proteasome activity and perturbs proteasome structure. We speculate that perturbations of proteasome structure might contribute to the cytotoxic effects of unfolded protein complexes that invade host cells

Subchronic toxicity of Baltic herring oil and its fractions in the rat II: Clinical observations and toxicological parameters

This study aimed to increase the knowledge about the toxicity of fish-derived organohalogen pollutants in mammals. The strategy chosen was to separate organohalogen pollutants derived from Baltic herring (Clupea harengus) fillet, in order to obtain fractions with differing proportions of identified and unidentified halogenated pollutants, and to perform a subchronic toxicity study in rats, essentially according to the OECD guidelines, at three dose levels. Nordic Sea Iodda (Mallotus villosus) oil, with low levels of persistent organohalogen pollutants, was used as an additional control diet. The toxicological examination showed that exposure to Baltic herring oil and its fractions at dose levels corresponding to a human intake in the range of 1.6 to 34.4 kg Baltic herring per week resulted in minimal effects. The spectrum of effects was similar to that, which is observed after low-level exposure to pollutants such as chlorinated dibenzo-p-dioxins and dibenzofurans (CDD/F) and chlorinated biphenyls, despite the fact that these contaminants contribute to a minor part of the extractable organically bound chlorine (EOC1). The study confirmed previous findings that induction of hepatic ethoxyresorufin deethylase (EROD) activity takes place at daily intake levels 0.15 ng fish-derived CDD/F-TEQs/kg body weight. The study also demonstrated that hepatic vitamin A reduction takes place at somewhat higher daily exposure levels, i.e. 0.16-0.30 ng fish-derived CDD/F-TEQs/kg body weight. Halogenated fatty acids, the major component of EOC1, could not be linked to any of the measured effects. From a risk management point of view, the study provides important new information of effect levels for Ah-receptor mediated responses following low level exposure to organohalogen compounds from a matrix relevant for human exposure

Prevalence, clinical investigation, and management of gallbladder disease in Rett syndrome

AIM: This study determined the prevalence of cholelithiasis and/or cholecystectomy in Rett syndrome, described gallbladder function in a clinical cohort, and identified recommendations for assessment and management of gallbladder disease. METHOD The incidence of cholelithiasis/cholecystectomy was estimated from data describing 270 and 681 individuals with a pathogenic MECP2 mutation in the Australian Rett Syndrome Database and the International Rett Syndrome Phenotype Database respectively. Gallbladder function in 25 females (mean age 16y 5mo, SD 20y 7mo, range 3y 5mo–47y 10mo) with Rett syndrome (RTT) was evaluated with clinical assessment and ultrasound of the gallbladder. The Delphi technique was used to develop assessment and treatment recommendations. RESULTS: The incidence rate for cholelithiasis and/or cholecystectomy was 2.3 (95% confidence interval [CI] 1.1–4.2) and 1.8 (95% CI 1.0–3.0) per 1000 person-years in the Australian and International Databases respectively. The mean contractility index of the gallbladder for the clinical sample was 46.5% (SD 38.3%), smaller than for healthy individuals but similar to children with Down syndrome, despite no clinical symptoms. After excluding gastroesophageal reflux, gallbladder disease should be considered as a cause of abdominal pain in RTT and cholecystectomy recommended if symptomatic. INTERPRETATION: Gallbladder disease is relatively common in RTT and should be considered in the differential diagnosis of abdominal pain in RTT