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• The low-level nuclear threatEurope is making a good start on learning about the health risks of low-dose radiation with a programme to share cold-war data and set research priorities. But the effort needs to be global.
• Damage limitation
Spider webs are designed to cope with stress and disruption, favouring repair over rebuilding.
• Cancer: Drug drives cancer stem cells
Cancer drugs that attack tumour-sustaining blood vessels may spur proliferation of the stem cells that contribute to the disease.One such drug, bevacizumab, fails to prolong the survival of patients with advanced breast cancers, and studies have shown that patients on similar drugs often relapse.
• Geology: Explosion in Death Valley
The volcanic eruption responsible for the giant Ubehebe Crater in California's Death Valley may have occurred more recently than previously thought. This could mean that the risk of similar explosions happening today is higher than anticipated.When magma encounters groundwater, distinctive explosions, such as those
• Informed consent on trial
Lengthy, complicated documents leave many clinical-trial participants in the dark about the risks they face.
• Nonlinear material behaviour of spider silk yields robust webs
Natural materials are renowned for exquisite designs that optimize function, as illustrated by the elasticity of blood vessels, the toughness of bone and the protection offered by nacre. Particularly intriguing are spider silks, with studies having explored properties ranging from their protein sequence to the geometry of a web. This material system, highly adapted to meet a spider?s many needs, has superior mechanical properties. In spite of much research into the molecular design underpinning the outstanding performance of silk fibres, and into the mechanical characteristics of web-like structures, it remains unknown how the mechanical characteristics of spider silk contribute to the integrity and performance of a spider web. Here we report web deformation experiments and simulations that identify the nonlinear response of silk threads to stress?involving softening at a yield point and substantial stiffening at large strain until failure?as being crucial to localize load-induced deformation and resulting in mechanically robust spider webs. Control simulations confirmed that a nonlinear stress response results in superior resistance to structural defects in the web compared to linear elastic or elastic?plastic (softening) material behaviour. We also show that under distributed loads, such as those exerted by wind, the stiff behaviour of silk under small deformation, before the yield point, is essential in maintaining the web?s structural integrity. The superior performance of silk in webs is therefore not due merely to its exceptional ultimate strength and strain, but arises from the nonlinear response of silk threads to strain and their geometrical arrangement in a web.
• Mutations in kelch-like 3 and cullin 3 cause hypertension and electrolyte abn...
Hypertension affects one billion people and is a principal reversible risk factor for cardiovascular disease. Pseudohypoaldosteronism type II (PHAII), a rare Mendelian syndrome featuring hypertension, hyperkalaemia and metabolic acidosis, has revealed previously unrecognized physiology orchestrating the balance between renal salt reabsorption and K+ and H+ excretion. Here we used exome sequencing to identify mutations in kelch-like 3 (KLHL3) or cullin 3 (CUL3) in PHAII patients from 41 unrelated families. KLHL3 mutations are either recessive or dominant, whereas CUL3 mutations are dominant and predominantly de novo. CUL3 and BTB-domain-containing kelch proteins such as KLHL3 are components of cullin?RING E3 ligase complexes that ubiquitinate substrates bound to kelch propeller domains. Dominant KLHL3 mutations are clustered in short segments within the kelch propeller and BTB domains implicated in substrate and cullin binding, respectively. Diverse CUL3 mutations all result in skipping of exon 9, producing an in-frame deletion. Because dominant KLHL3 and CUL3 mutations both phenocopy recessive loss-of-function KLHL3 mutations, they may abrogate ubiquitination of KLHL3 substrates. Disease features are reversed by thiazide diuretics, which inhibit the Na?Cl cotransporter in the distal nephron of the kidney; KLHL3 and CUL3 are expressed in this location, suggesting a mechanistic link between KLHL3 and CUL3 mutations, increased Na?Cl reabsorption, and disease pathogenesis. These findings demonstrate the utility of exome sequencing in disease gene identification despite the combined complexities of locus heterogeneity, mixed models of transmission and frequent de novo mutation, and establish a fundamental role for KLHL3 and CUL3 in blood pressure, K+ and pH homeostasis.
Nature Journals
• Hsp90 stress potentiates rapid cellular adaptation through induction of aneup...Aneuploidy?the state of having uneven numbers of chromosomes?is a hallmark of cancer and a feature identified in yeast from diverse habitats. Recent studies have shown that aneuploidy is a form of large-effect mutation that is able to confer adaptive phenotypes under diverse stress conditions. Here we investigate whether pleiotropic stress could induce aneuploidy in budding yeast (Saccharomyces cerevisae). We show that whereas diverse stress conditions can induce an increase in chromosome instability, proteotoxic stress, caused by transient Hsp90 (also known as Hsp82 or Hsc82) inhibition or heat shock, markedly increased chromosome instability to produce a cell population with high karyotype diversity. The induced chromosome instability is linked to an evolutionarily conserved role for the Hsp90 chaperone complex in kinetochore assembly. Continued growth in the presence of an Hsp90 inhibitor resulted in the emergence of drug-resistant colonies with chromosome XV gain. This drug-resistance phenotype is a quantitative trait involving copy number increases of at least two genes located on chromosome XV. Short-term exposure to Hsp90 stress potentiated fast adaptation to unrelated cytotoxic compounds by means of different aneuploid chromosome stoichiometries. These findings demonstrate that aneuploidy is a form of stress-inducible mutation in eukaryotes, capable of fuelling rapid phenotypic evolution and drug resistance, and reveal a new role for Hsp90 in regulating the emergence of adaptive traits under stress.
• Genetic contributions to stability and change in intelligence from childhood ...
Understanding the determinants of healthy mental ageing is a priority for society today. So far, we know that intelligence differences show high stability from childhood to old age and there are estimates of the genetic contribution to intelligence at different ages. However, attempts to discover whether genetic causes contribute to differences in cognitive ageing have been relatively uninformative. Here we provide an estimate of the genetic and environmental contributions to stability and change in intelligence across most of the human lifetime. We used genome-wide single nucleotide polymorphism (SNP) data from 1,940 unrelated individuals whose intelligence was measured in childhood (age 11 years) and again in old age (age 65, 70 or 79 years). We use a statistical method that allows genetic (co)variance to be estimated from SNP data on unrelated individuals. We estimate that causal genetic variants in linkage disequilibrium with common SNPs account for 0.24 of the variation in cognitive ability change from childhood to old age. Using bivariate analysis, we estimate a genetic correlation between intelligence at age 11 years and in old age of 0.62. These estimates, derived from rarely available data on lifetime cognitive measures, warrant the search for genetic causes of cognitive stability and change.
• Galectin 8 targets damaged vesicles for autophagy to defend cells against bac...
Autophagy defends the mammalian cytosol against bacterial infection. Efficient pathogen engulfment is mediated by cargo-selecting autophagy adaptors that rely on unidentified pattern-recognition or danger receptors to label invading pathogens as autophagy cargo, typically by polyubiquitin coating. Here we show in human cells that galectin 8 (also known as LGALS8), a cytosolic lectin, is a danger receptor that restricts Salmonella proliferation. Galectin 8 monitors endosomal and lysosomal integrity and detects bacterial invasion by binding host glycans exposed on damaged Salmonella-containing vacuoles. By recruiting NDP52 (also known as CALCOCO2), galectin 8 activates antibacterial autophagy. Galectin-8-dependent recruitment of NDP52 to Salmonella-containing vesicles is transient and followed by ubiquitin-dependent NDP52 recruitment. Because galectin 8 also detects sterile damage to endosomes or lysosomes, as well as invasion by Listeria or Shigella, we suggest that galectin 8 serves as a versatile receptor for vesicle-damaging pathogens. Our results illustrate how cells deploy the danger receptor galectin 8 to combat infection by monitoring endosomal and lysosomal integrity on the basis of the specific lack of complex carbohydrates in the cytosol.
• Lowland?upland migration of sauropod dinosaurs during the Late Jurassic epoch
Sauropod dinosaurs were the largest vertebrates ever to walk the Earth, and as mega-herbivores they were important parts of terrestrial ecosystems. In the Late Jurassic-aged Morrison depositional basin of western North America, these animals occupied lowland river-floodplain settings characterized by a seasonally dry climate. Massive herbivores with high nutritional and water needs could periodically experience nutritional and water stress under these conditions, and thus the common occurrence of sauropods in this basin has remained a paradox. Energetic arguments and mammalian analogues have been used to suggest that migration allowed sauropods access to food and water resources over a wide region or during times of drought or both, but there has been no direct support for these hypotheses. Here we compare oxygen isotope ratios (?18O) of tooth-enamel carbonate from the sauropod Camarasaurus with those of ancient soil, lake and wetland (that is, ?authigenic?) carbonates that formed in lowland settings. We demonstrate that certain populations of these animals did in fact undertake seasonal migrations of several hundred kilometres from lowland to upland environments. This ability to describe patterns of sauropod movement will help to elucidate the role that migration played in the ecology and evolution of gigantism of these and associated dinosaurs.
• Spinal device cancer risk
• Bringing business risk into sharp focus
• Toll-like receptor activation suppresses ER stress factor CHOP and translatio...
Endoplasmic reticulum (ER) stress and activation of the unfolded protein response inhibits de novo protein translation and activates CHOP. However, the long-term induction of these pathways in response to prolonged ER stress would be detrimental. Tabas and colleagues now reveal a mechanism through which Toll-like receptor signalling suppresses CHOP activation and promotes protein translation, thus allowing cells to adapt to persistent ER stress.
• A genome-wide association study in Chinese men identifies three risk loci for...
Jiahao Sha, Xinru Wang, Hongbing Shen and colleagues report a genome-wide association study of non-obstructive azoospermia in Chinese men. They identify common variants near three genes (PRMT6, PEX10 and SOX5) associated with this form of male infertility.
• Meta-analysis of genome-wide association studies identifies three new risk lo...
Lavinia Paternoster and colleagues report a meta-analysis of genome-wide association studies of atopic dermatitis. They report three newly identified associated loci near OVOL1 and ACTL9 and in KIF3A.
• HHS ruling on Plan B introduces new risk for drugmakers
• Finding a sirtuin truth in Huntington's disease
The search for compounds to treat neurodegenerative disorders is especially pressing given the rapidly growing elderly human population and has led to the consideration of sirtuin proteins as potential therapeutic candidates. Two studies now report that modulating the expression of the sirtuin Sirt1 has therapeutic benefit in Huntington's disease mouse models and identify putative downstream targets of Sirt1 involved in improved disease outcomes (pages 159?165 and 153?158).
• Tumor strengths and frailties: Cancer SUMmOns Otto's metabolism
Cancer cells thrive owing to different means of survival and proliferation. But despite growing understanding of the biology of cancer and the mechanism of tumorigenesis, complete knowledge of what causes cancer is still lacking. There are multiple hypotheses as to what drives cells to become malignant. One of them is the Warburg effect, which supports that an increase in glycolysis over oxidative respiration, even in the presence of oxygen, may be the cause of cancer. But this premise has not yet been confirmed. In 'Bench to Bedside', Michael Ohh peruses a recent study showing a common mutation in people with renal cell carcinoma and melanoma that may rekindle the debate as to whether a metabolic switch is a major driver in cancer and whether it has potential as a therapeutic target. Every so often, an 'old' drug seems to work for a condition that was not previously known. Two recent human studies show that aspirin can prevent colorectal cancer in people genetically predisposed to this disease after several years after treatment. In 'Bedside to Bench', Patrick Maxwell discusses the possible mechanisms of action of aspirin in decreasing the risk of developing colorectal cancer.
• The problems and promises of research into human immunology and autoimmune di...
Translational research in autoimmunity is hampered by a number of hurdles, including a lack of knowledge regarding initiating and pathologically relevant autoantigens, the low frequency of autoreactive pathogenic B and T cells, difficulty in accessing the affected tissue, differences between self-reactive and pathogen-specific lymphocytes, a lack of etiologically relevant preclinical animal models and the heterogeneity of disease presentation. Given the need for biomarkers and new therapeutics, it is imperative that these hurdles be surmounted.
• Recent advances in the genetic epidemiology and molecular genetics of substan...
This is a review of current advances in the genetics of substance use disorders (SUDs), discussing how both genetic and environmental sources of risk are required to develop a complete picture of SUD etiology.
Nature Reviews
• Signalling: SRC and survivalCancer cells target active SRC for autophagy when SRC signalling is deregulated through the loss of focal adhesion kinase.
• Targeting MET in cancer: rationale and progress
Uncontrolled cell survival, growth, angiogenesis and metastasis are essential hallmarks of cancer. Genetic and biochemical data have demonstrated that the growth and motility factor hepatocyte growth factor/scatter factor (HGF/SF) and its receptor, the tyrosine kinase MET, have a causal role in all of these processes,
• Rare and common variants: twenty arguments
Genome-wide association studies have greatly improved our understanding of the genetic basis of disease risk. The fact that they tend not to identify more than a fraction of the specific causal loci has led to divergence of opinion over whether most of the variance is
• Familial risks in understanding type 1 diabetes genetics
There have been impressive advances in the genetics of type 1 diabetes (T1D) that are increasingly being translated into a greater understanding of the disease mechanisms, as reviewed in this journal by Polychronakos and Li (Understanding type 1 diabetes through genetics: advances and prospects.
• Response to 'Familial risks in understanding type 1 diabetes genetics'
Relating to our Review article published in this journal (Understanding type 1 diabetes through genetics: advances and prospects. Nature Reviews Genetics12, 781?792), we thank Kari Hemminki (Familial risks in understanding type 1 diabetes genetics. Nature Reviews Genetics 17 Jan
• Post-translational modification: Inactivating PTP1B upon ER stress
Sulphydration inhibits the phosphatase activity of PTP1B in response to ER stress.
• The unfolded protein response: controlling cell fate decisions under ER stres...
Protein-folding stress at the endoplasmic reticulum (ER) is a salient feature of specialized secretory cells and is also involved in the pathogenesis of many human diseases. ER stress is buffered by the activation of the unfolded protein response (UPR), a homeostatic signalling network that orchestrates