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Huge new Facebook data leak exposed intimate details of 3m users

Genetics - пн, 2018-05-14 15:17
Data from millions of Facebook users, including their answers to intimate questionnaires, was left exposed online for anyone to access, a New Scientist investigation has found
Категории: Biology

Huge new Facebook data leak exposed intimate details of 3m users

HIV and AIDS - пн, 2018-05-14 15:17
Data from millions of Facebook users, including their answers to intimate questionnaires, was left exposed online for anyone to access, a New Scientist investigation has found
Категории: Healthcare, Science and society

Doing Dry January lowers cancer-promoting proteins in your blood

Genetics - пн, 2018-05-14 14:15
Stopping drinking for just one month is enough to dramatically lower the levels of hormone-like chemicals in your blood that help cancer to develop and spread
Категории: Biology

Doing Dry January lowers cancer-promoting proteins in your blood

Genetically modified organisms (GMO) - пн, 2018-05-14 14:15
Stopping drinking for just one month is enough to dramatically lower the levels of hormone-like chemicals in your blood that help cancer to develop and spread
Категории: Science and society

Doing Dry January lowers cancer-promoting proteins in your blood

HIV and AIDS - пн, 2018-05-14 14:15
Stopping drinking for just one month is enough to dramatically lower the levels of hormone-like chemicals in your blood that help cancer to develop and spread
Категории: Healthcare, Science and society

Deluded drivers: The startling discovery that changed psychology

Genetically modified organisms (GMO) - пн, 2018-05-14 14:00
A 1960s survey of drivers hospitalised after accidents found that they still rated their skills as exceptional – and we all have similar blind spots
Категории: Science and society

Deluded drivers: The startling discovery that changed psychology

Genetics - пн, 2018-05-14 14:00
A 1960s survey of drivers hospitalised after accidents found that they still rated their skills as exceptional – and we all have similar blind spots
Категории: Biology

It is worth valuing trees, but all deserve our respect

Genetically modified organisms (GMO) - пн, 2018-05-14 12:00
The benefits trees bring to our lives are now being quantified by a band of treeconomists, an approach that could help us give trees the respect they deserve
Категории: Science and society

It is worth valuing trees, but all deserve our respect

Genetics - пн, 2018-05-14 12:00
The benefits trees bring to our lives are now being quantified by a band of treeconomists, an approach that could help us give trees the respect they deserve
Категории: Biology

It is worth valuing trees, but all deserve our respect

HIV and AIDS - пн, 2018-05-14 12:00
The benefits trees bring to our lives are now being quantified by a band of treeconomists, an approach that could help us give trees the respect they deserve
Категории: Healthcare, Science and society

Animals & Us: An art show about how we interact with creatures

Genetically modified organisms (GMO) - вс, 2018-05-13 12:00
A polar bear loose in the streets of a famous seaside town sets the stage for an art show to ask tough questions
Категории: Science and society

Animals & Us: An art show about how we interact with creatures

Genetics - вс, 2018-05-13 12:00
A polar bear loose in the streets of a famous seaside town sets the stage for an art show to ask tough questions
Категории: Biology

NASA is sending an autonomous helicopter to Mars in 2020

Genetically modified organisms (GMO) - сб, 2018-05-12 01:00
The Mars 2020 rover, which will look for signs of life on the Red Planet, will be carrying another small spacecraft along with it: the Mars Helicopter
Категории: Science and society

NASA is sending an autonomous helicopter to Mars in 2020

Genetics - сб, 2018-05-12 01:00
The Mars 2020 rover, which will look for signs of life on the Red Planet, will be carrying another small spacecraft along with it: the Mars Helicopter
Категории: Biology

NASA is sending an autonomous helicopter to Mars in 2020

HIV and AIDS - сб, 2018-05-12 01:00
The Mars 2020 rover, which will look for signs of life on the Red Planet, will be carrying another small spacecraft along with it: the Mars Helicopter
Категории: Healthcare, Science and society

Death and population dynamics affect mutation rate estimates and evolvability under stress in bacteria

PLOS Biology (new articles) - пт, 2018-05-11 23:00

by Antoine Frenoy, Sebastian Bonhoeffer

The stress-induced mutagenesis hypothesis postulates that in response to stress, bacteria increase their genome-wide mutation rate, in turn increasing the chances that a descendant is able to better withstand the stress. This has implications for antibiotic treatment: exposure to subinhibitory doses of antibiotics has been reported to increase bacterial mutation rates and thus probably the rate at which resistance mutations appear and lead to treatment failure. More generally, the hypothesis posits that stress increases evolvability (the ability of a population to generate adaptive genetic diversity) and thus accelerates evolution. Measuring mutation rates under stress, however, is problematic, because existing methods assume there is no death. Yet subinhibitory stress levels may induce a substantial death rate. Death events need to be compensated by extra replication to reach a given population size, thus providing more opportunities to acquire mutations. We show that ignoring death leads to a systematic overestimation of mutation rates under stress. We developed a system based on plasmid segregation that allows us to measure death and division rates simultaneously in bacterial populations. Using this system, we found that a substantial death rate occurs at the tested subinhibitory concentrations previously reported to increase mutation rate. Taking this death rate into account lowers and sometimes removes the signal for stress-induced mutagenesis. Moreover, even when antibiotics increase mutation rate, we show that subinhibitory treatments do not increase genetic diversity and evolvability, again because of effects of the antibiotics on population dynamics. We conclude that antibiotic-induced mutagenesis is overestimated because of death and that understanding evolvability under stress requires accounting for the effects of stress on population dynamics as much as on mutation rate. Our goal here is dual: we show that population dynamics and, in particular, the numbers of cell division are crucial but neglected parameters in the evolvability of a population, and we provide experimental and computational tools and methods to study evolvability under stress, leading to a reassessment of the magnitude and significance of the stress-induced mutagenesis paradigm.
Категории: Biology, Journals

Tumor-associated neutrophils suppress pro-tumoral IL-17+ γδ T cells through induction of oxidative stress

PLOS Biology (new articles) - пт, 2018-05-11 23:00

by Sofia Mensurado, Margarida Rei, Telma Lança, Marianna Ioannou, Natacha Gonçalves-Sousa, Hiroshi Kubo, Marie Malissen, Venizelos Papayannopoulos, Karine Serre, Bruno Silva-Santos

Interleukin 17 (IL-17)–producing γδ T cells (γδ17 T cells) have been recently found to promote tumor growth and metastasis formation. How such γδ17 T-cell responses may be regulated in the tumor microenvironment remains, however, largely unknown. Here, we report that tumor-associated neutrophils can display an overt antitumor role by strongly suppressing γδ17 T cells. Tumor-associated neutrophils inhibited the proliferation of murine CD27− Vγ6+ γδ17 T cells via induction of oxidative stress, thereby preventing them from constituting the major source of pro-tumoral IL-17 in the tumor microenvironment. Mechanistically, we found that low expression of the antioxidant glutathione in CD27− γδ17 T cells renders them particularly susceptible to neutrophil-derived reactive oxygen species (ROS). Consistently, superoxide deficiency, or the administration of a glutathione precursor, rescued CD27− Vγ6+ γδ17 T-cell proliferation in vivo. Moreover, human Vδ1+ γδ T cells, which contain most γδ17 T cells found in cancer patients, also displayed low glutathione levels and were potently inhibited by ROS. This work thus identifies an unanticipated, immunosuppressive yet antitumoral, neutrophil/ROS/γδ17 T-cell axis in the tumor microenvironment.
Категории: Biology, Journals

Metabolic benefits of inhibition of p38α in white adipose tissue in obesity

PLOS Biology (new articles) - пт, 2018-05-11 23:00

by Shengjie Zhang, Hongchao Cao, Yan Li, Yanyan Jing, Shengnan Liu, Cheng Ye, Hui Wang, Shuxian Yu, Chengyuan Peng, Lijian Hui, Yu-cheng Wang, Haibing Zhang, Feifan Guo, Qiwei Zhai, Hui Wang, Ruimin Huang, Ling Zhang, Jingjing Jiang, Wei Liu, Hao Ying

p38 has long been known as a central mediator of protein kinase A (PKA) signaling in brown adipocytes, which positively regulate the transcription of uncoupling protein 1 (UCP-1). However, the physiological role of p38 in adipose tissues, especially the white adipose tissue (WAT), is largely unknown. Here, we show that mice lacking p38α in adipose tissues display a lean phenotype, improved metabolism, and resistance to diet-induced obesity. Surprisingly, ablation of p38α causes minimal effects on brown adipose tissue (BAT) in adult mice, as evident from undetectable changes in UCP-1 expression, mitochondrial function, body temperature (BT), and energy expenditure. In contrast, genetic ablation of p38α in adipose tissues not only markedly facilitates the browning in WAT upon cold stress but also prevents diet-induced obesity. Consistently, pharmaceutical inhibition of p38α remarkably enhances the browning of WAT and has metabolic benefits. Furthermore, our data suggest that p38α deficiency promotes white-to-beige adipocyte reprogramming in a cell-autonomous manner. Mechanistically, inhibition of p38α stimulates the UCP-1 transcription through PKA and its downstream cAMP-response element binding protein (CREB), which form a positive feedback loop that functions to reinforce the white-to-beige phenotypic switch during cold exposure. Together, our study reveals that inhibition of p38α is able to promote WAT browning and confer metabolic benefits. Our study also indicates that p38α in WAT represents an exciting pharmacological target to combat obesity and metabolic diseases.
Категории: Biology, Journals

Hey1- and p53-dependent TrkC proapoptotic activity controls neuroblastoma growth

PLOS Biology (new articles) - пт, 2018-05-11 23:00

by Marie Ménard, Clélia Costechareyre, Gabriel Ichim, Jonathan Blachier, David Neves, Loraine Jarrosson-Wuilleme, Reinhard Depping, Jan Koster, Pierre Saintigny, Patrick Mehlen, Servane Tauszig-Delamasure

The neurotrophin-3 (NT-3) receptor tropomyosin receptor kinase C (TrkC/NTRK3) has been described as a dependence receptor and, as such, triggers apoptosis in the absence of its ligand NT-3. This proapoptotic activity has been proposed to confer a tumor suppressor activity to this classic tyrosine kinase receptor (RTK). By investigating interacting partners that might facilitate TrkC-induced cell death, we have identified the basic helix-loop-helix (bHLH) transcription factor Hey1 and importin-α3 (karyopherin alpha 4 [KPNA4]) as direct interactors of TrkC intracellular domain, and we show that Hey1 is required for TrkC-induced apoptosis. We propose here that the cleaved proapoptotic portion of TrkC intracellular domain (called TrkC killer-fragment [TrkC-KF]) is translocated to the nucleus by importins and interacts there with Hey1. We also demonstrate that Hey1 and TrkC-KF transcriptionally silence mouse double minute 2 homolog (MDM2), thus contributing to p53 stabilization. p53 transcriptionally regulates the expression of TrkC-KF cytoplasmic and mitochondrial interactors cofactor of breast cancer 1 (COBRA1) and B cell lymphoma 2–associated X (BAX), which will subsequently trigger the intrinsic pathway of apoptosis. Of interest, TrkC was proposed to constrain tumor progression in neuroblastoma (NB), and we demonstrate in an avian model that TrkC tumor suppressor activity requires Hey1 and p53.
Категории: Biology, Journals

Towing icebergs to Cape Town is a poor way to halt water crisis

Genetics - пт, 2018-05-11 20:00
Hauling chunks of polar ice to dry regions to provide fresh water sounds tempting but there are many reasons to reject it, says Olive Heffernan
Категории: Biology