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The response by the author. Subject Categories: S&S: Economics & Business, S&S: Ethics

I thank Michael Bronstein and Sophia Vinogradov for their interest and comments. I would like to respond to a few of their points.First, I agree with the authors that empirical studies should be conducted to validate any approaches to prevent the spread of misinformation before their implementation. Nonetheless, I think that the ideas I have proposed may be worth further discussion and inspire empirical studies to test their effectiveness.Second, the authors warn that informing about the imperfections of scientific research may undermine trust in science and scientists, which could result in higher vulnerability to online health misinformation (Roozenbeek et al, 2020; Bronstein & Vinogradov, 2021). I believe that transparency about limitations and problems in research does not necessarily have to diminish trust in science and scientists. On the contrary, as Veit et al put it, “such honesty… is a prerequisite for maintaining a trusting relationship between medical institutions (and practitioners) and the public” (Veit et al, 2021). Importantly, to give an honest picture of scientific research, information about its limitations should be put in adequate context. In particular, the public also should be aware that “good science” is being done by many researchers; we do have solid evidence of effectiveness of many medical interventions; and efforts are being taken to address the problems related to quality of research.Third, Bronstein and Vinogradov suggest that false and dangerous information should be censored. I agree with the authors that “[c]ensorship can prevent individuals from being exposed to false and potentially dangerous ideas” (Bronstein & Vinogradov, 2021). I also recognize that some information is false beyond any doubt and its spread may be harmful. What I am concerned about are, among others, the challenges related to defining what is dangerous and false information and limiting censorship only to this kind of information. For example, on what sources should decisions to censor be based and who should make such decisions? Anyone, whether an individual or an organization, with a responsibility to censor information will likely not only be prone to mistakes, but also to abuses of power to foster their interests. Do the benefits we want to achieve by censorship outweigh the potential risks?Fourth, we need rigorous empirical studies examining the actual impact of medical misinformation. What exactly are the harms we try to protect against and what is their scale? This information is necessary to choose proportionte and effective measures to reduce the harms. Bronstein and Vinogradov give an example of a harm which may be caused by misinformation—an increase in methanol poisoning in Iran. Yet, as noticed by the authors, misinformation is not the sole factor in this case; there are also cultural and other contexts (Arasteh et al, 2020; Bronstein & Vinogradov, 2021). Importantly, the methods of studies exploring the effects of misinformation should be carefully elaborated, especially when study participants are asked to self‐report. A recent study suggests that some claims about the prevalence of dangerous behaviors, such as drinking bleach, which may have been caused by misinformation are largely exaggerated due to the presence of problematic respondents in surveys (preprint: Litman et al, 2021).Last but not least, I would like to call attention to the importance of how veracity of information is determined in empirical studies on misinformation. For example, in a study of Roozenbeek et al, cited by Bronstein and Vinogradov, the World Health Organization (WHO) was used as reliable source of information, which raises questions. For instance, Roozenbeek et al (2020) used a statement “the coronavirus was bioengineered in a military lab in Wuhan” as an example of false information, relying on the judgment of the WHO found on its “mythbusters” website (Roozenbeek et al, 2020). Yet, is there a solid evidence to claim that this statement is false? At present, at least some scientists declare that we cannot rule out that the virus was genetically manipulated in a laboratory (Relman, 2020; Segreto & Deigin, 2020). Interestingly, the WHO also no longer excludes such a possibility and has launched an investigation on this issue (https://www.who.int/health‐topics/coronavirus/origins‐of‐the‐virus, https://www.who.int/emergencies/diseases/novel‐coronavirus‐2019/media‐resources/science‐in‐5/episode‐21‐‐‐covid‐19‐‐‐origins‐of‐the‐sars‐cov‐2‐virus); the information about the laboratory origin of the virus being false is no longer present on the WHO “mythbusters” website (https://www.who.int/emergencies/diseases/novel‐coronavirus‐2019/advice‐for‐public/myth‐busters). Against this backdrop, some results of the study by Roozenbeek et al (2020) seem misleading. In particular, the perception of the reliability of the statement about bioengineered virus by study participants in Roozenbeek et al (2020) does not reflect the susceptibility to misinformation, as intended by the researchers, but rather how the respondents perceive reliability of uncertain information.I hope that discussion and research on these and related issues will continue.  相似文献   

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Debates about the source of antibodies and their use are confusing two different issues. A ban on life immunization would have no repercussions on the quality of antibodies. Subject Categories: S&S: Economics & Business, Methods & Resources, Chemical Biology

There is an ongoing debate on how antibodies are being generated, produced and used (Gray, 2020; Marx, 2020). Or rather, there are two debates, which are not necessarily related to each other. The first one concerns the quality of antibodies used in scientific research and the repercussions for the validity of results (Bradbury & Pluckthun, 2015). The second debate is about the use of animals to generate and produce antibodies. Although these are two different issues, we observe that the debates have become entangled with arguments for one topic incorrectly being used to motivate the other and vice versa. This is not helpful, and we should disentangle the knot.Polyclonal antibodies are being criticized because they suffer from cross‐reactivity, high background and batch‐to‐batch variation (Bradbury & Pluckthun, 2015). Monoclonal antibodies produced from hybridomas are criticized because they often lack specificity owing to genetic heterogeneity introduced during hybridoma generation that impairs the quality of the monoclonals (Bradbury et al, 2018). These are valid criticisms and producing antibodies in a recombinant manner will, indeed, help to improve quality and specificity. But a mediocre antibody will remain a mediocre antibody, no matter how it is produced. Recombinant methods will just produce a mediocre antibody more consistently.Getting a good antibody is not easy and much depends on the nature and complexity of the antigen. And low‐quality antibodies are often the result of poor screening, poor quality control, incomplete characterization and the lack of international standards. Nevertheless, the technologies to ensure good selection and to guarantee consistent quality are much more advanced than a decade ago, and scientists and antibody producers should implement these to deliver high‐quality antibodies. Whether antibodies are generated by animal immunization or from naïve or synthetic antibody libraries is less relevant; they can all be produced recombinantly, and screening and characterization are needed in all cases to determine quality, and if the antibody is fit for purpose.But criticisms on the quality of many antibodies and pleas for switching to recombinant production of antibodies cannot be mixed up with a call to ban animal immunization. The EU Reference Laboratory for Alternatives to Animal Testing (EURL ECVAM) recently published a recommendation to stop using animals for generating and producing antibodies for scientific, diagnostic and even therapeutic applications (EURL ECVAM, 2020). This recommendation is mainly supported by scientists who seem to be biased towards synthetic antibody technology for various reasons. Their main argument is that antibodies derived from naïve or synthetic libraries are a valid (and exclusive) alternative. But are they?One can certainly select antibodies from non‐immune libraries, and, depending on the antigen and the type of application, these antibodies can be fit for purpose. In fact, a few of such antibodies have made it to the market as therapeutics, Adalimumab (Humira®) being a well‐known example. But up to now, the vast majority of antibodies continues to come from animal immunization (Lu et al, 2020). And there is a good reason for that. It is generally possible to generate a few positive hits in a naïve/synthetic library; and the more diverse the library, the more hits one is likely to get. But many decades of experience with immunization of animals—especially when they are outbred—shows that they generate larger amounts of antibodies with superior properties. And the more complex your antigen is, the more the balance swings towards animal immunization if you want to have a guarantee for success.There are different factors at work here. First, the immune system of mammals has evolved over millions of years to efficiently produce excellent antibodies against a very diverse range of antigens. Second, presenting the antigen multiple times in its desired (native) conformation to the animal immune system exploits the natural maturation process to fine‐tune the immune response against particular qualities. Another factor is that in vivo maturation seems to select against negative properties such as self‐recognition and aggregation. It also helps to select for important properties that go beyond mere molecular recognition (Jain et al, 2017). In industrial parlance, antibodies from animal immunization are more “developable” and have favourable biophysical properties (Lonberg, 2005). Indeed, the failure rate for antibodies selected from naïve or synthetic libraries is significantly higher.Of course, the properties of synthetic antibodies selected from non‐immune libraries can be further matured in vitro, for example by light chain shuffling or targeted mutagenesis of the complementarity determining region (CDR). While this method has become more sophisticated over the years, it remains a very complex and iterative process without guarantee that it produces a high‐quality antibody.Antibodies are an ever more important tool in scientific research and a growing area in human and veterinary therapeutics. Major therapeutic breakthroughs in immunology and oncology in the past decades are based on antibodies (Lu et al, 2020). The vast majority of these therapeutic antibodies were derived from animals. An identical picture appears when you look at the antibodies in fast‐track development to combat the current COVID‐19 crisis: again, the vast majority are either derived from patients or from animal immunizations. The same holds true for antibodies that are used in diagnostics and epidemiologic studies for COVID‐19.It is for that reason that we need the tools and methods that guarantee antibodies of the highest quality and provide the best chance for success. The COVID‐19 pandemic is only one illustration of this need. If we block access to these tools, both scientific research and society at large will be negatively impacted. We therefore should not limit ourselves to naïve and synthetic libraries. Animal immunization remains an inevitable method that needs to stay. But we all agree that these immunizations must be performed under best practice to further reduce the harm to animals.  相似文献   

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The EU''s Biodiversity Strategy for 2030 makes great promises about halting the decline of biodiversity but it offers little in terms of implementation. Subject Categories: S&S: Economics & Business, Ecology, S&S: Ethics

Earth is teeming with a stunning variety of life forms. Despite hundreds of years of exploration and taxonomic research, and with 1.2 million species classified, we still have no clear picture of the real extent of global biodiversity, with estimates ranging from 3 to 100 million species. A highly quoted—although not universally accepted—study predicted some 8.7 million species, of which about 2.2 million are marine (Mora et al, 2011). Although nearly any niche on the surface of Earth has been colonized by life, species richness is all but evenly distributed. A large share of the known species is concentrated in relatively small areas, especially in the tropics (Fig 1). Ultimately, it is the network of the interactions among life forms and the physical environment that make up the global ecosystem we call biosphere and that supports life itself.Open in a separate windowFigure 1Biological hotspots of the worldA total of 36 currently recognized hotspots make up < 3% of the planet''s land area but harbor half of the world''s endemic plant species and 42% of all terrestrial vertebrates. Overall, hotspots have lost more than 80% of their original extension. Credit: Richard J. Weller, Claire Hoch, and Chieh Huang, 2017, Atlas for the End of the World, http://atlas‐for‐the‐end‐of‐the‐world.com/. Reproduced with permission.Driven by a range of complex and interwoven causes–such as changes in land and sea use, habitat destruction, overexploitation of organisms, climate change, pollution, and invasive species–biodiversity is declining at an alarming pace. A report by the Intergovernmental Science‐Policy Platform on Biodiversity and Ecosystem Services (IPBES) issued a clear warning: “An average of around 25 per cent of species in assessed animal and plant groups are threatened, suggesting that around 1 million species already face extinction, many within decades, unless action is taken to reduce the intensity of drivers of biodiversity loss. Without such action, there will be a further acceleration in the global rate of species extinction, which is already at least tens to hundreds of times higher than it has averaged over the past 10 million years” (IPBES, 2019) (Fig 2). Although focused on a smaller set of organisms, a more recent assessment by WWF has reached similar conclusions. Their Living Planet Index, that tracks the abundance of thousands of populations of mammals, birds, fish, reptiles, and amphibians around the world, shows a stark decline in monitored populations (WWF, 2020). As expected, the trend of biodiversity decline is not homogeneous with tropical areas paying a disproportionately high price, mostly because of unrestrained deforestation and exploitation of natural resources.Open in a separate windowFigure 2The global, rapid decline of biodiversity(A) Percentage of species threatened with extinction in taxonomic groups that have been assessed comprehensively, or through a “sampled” approach, or for which selected subsets have been assessed by the IUCN Red List of Threatened Species. Groups are ordered according to the best estimate, assuming that data‐deficient species are as threatened as non‐data deficient species. (B) Extinctions since 1500 for vertebrate groups. (C) Red List Index of species survival for taxonomic groups that have been assessed for the IUCN Red List at least twice. A value of 1 is equivalent to all species being categorized as Least Concern; a value of zero is equivalent to all species being classified as Extinct. Data for all panels from www.iucnredlist.org. Reproduced from (IPBES, 2019), with permission.
Driven by a range of complex and interwoven causes […] biodiversity is declining at an alarming pace.
Against this dire background, the EU has drafted a Biodiversity Strategy 2030, an ambitious framework aimed to tackling the key reasons behind biodiversity loss. The plan hinges around a few main elements, such as the establishment of protected areas for at least 30% of Europe''s lands and seas (Fig 3); a significant increase of biodiversity‐rich landscape features on agricultural land by establishing buffer zones like hedges and fallow fields; halting and reversing the decline of pollinators; and planting 3 billion trees by 2030 (https://ec.europa.eu/info/strategy/priorities‐2019‐2024/european‐green‐deal/actions‐being‐taken‐eu/eu‐biodiversity‐strategy‐2030_en). The budget for implementing these measures was set at €20 billion per year.Open in a separate windowFigure 3Natura 2000, the EU''s network of protected areasIn 2019, 18% of land in the EU was protected as Natura 2000, with the lowest share of protected land in Denmark (8%) and the highest in Slovenia (38%). In 2019, the largest national network of terrestrial Natura 2000 sites was located in Spain, covering 138,111 km2, followed by France (70,875 km2) and Poland (61,168 km2). Reproduced from Eurostat: https://ec.europa.eu/eurostat/statistics‐explained/index.php?title=Main_Page “Nature is vital for our physical and mental wellbeing, it filters our air and water, it regulates the climate and it pollinates our crops. But we are acting as if it didn''t matter, and losing it at an unprecedented rate”, said Virginijus Sinkevičius, Commissioner for the Environment, Oceans and Fisheries, at the press launch of the new EU action (https://ec.europa.eu/commission/presscorner/detail/en/ip_20_884). “This new Biodiversity Strategy builds on what has worked in the past, and adds new tools that will set us on a path to true sustainability, with benefits for all. The EU''s aim is to protect and restore nature, to contribute to economic recovery from the current crisis, and to lead the way for an ambitious global framework to protect biodiversity around the planet”.Environmental groups and other stakeholders have welcomed the EU''s pledge in principle. “This is a unique opportunity to shape a new society in harmony with nature”, applauded Wetlands International. “We must not forget that the biodiversity and climate crisis is a much bigger and persistent challenge for humanity than COVID‐19”, (https://europe.wetlands.org/news/welcoming‐the‐eu‐biodiversity‐strategy‐for‐2030/). EuroNatur, a foundation focused on conservation, stated that the goals set out by the new strategy provide a strong basis for improving the state of nature in the EU (www.euronatur.org).Alongside the voices of praise, however, many have expressed concerns that the strategy could turn into a little more than a wish list. “The big issue of the strategy is that while setting a goal for financial funds, the EU does not specify where the money is supposed to come from. It only says it should include ‘EU funds and national and private funding’”, commented the European Wilderness Society, an environmental advocacy non‐profit organization headquartered in Tamsweg, Austria. “Goals are important, but do not create change without an organized and sustainable implementation. It''s a good and ambitious document, but what is also obvious is the lack of strategy of how to implement it, and a lack of discussion of why previous documents of this type failed” (https://wilderness‐society.org/ambitious‐eu‐biodiversity‐strategy‐2030/).
Alongside the voices of praise, however, many have expressed concerns that the strategy could turn into a little more than a wish list.
The Institute for European Environmental Policy (IEEP) is on the same page. The sustainability think‐tank based in Brussels and London noted that the outgoing EU 2020 biodiversity strategy showed major implementation problems, especially because of lack of engagement at national level and of ad hoc legislation supporting the meeting of key targets. Therefore, “[it] can be argued that a legally binding approach to the biodiversity governance framework is urgently needed unless Member States and other key stakeholders can show greater intrinsic ownership to deliver on agreed objectives”, (https://ieep.eu/news/first‐impressions‐of‐the‐eu‐biodiversity‐strategy‐to‐2030). In addition, IEEP remarked that money is an issue, since the €20 billion figure appears more as an estimate than a certified obligation.“The intentions of the Commission are good and the strategy contains a number of measures and targets that can really make a difference. However, implementation depends critically on the member states and experiences with the Common Agricultural Policy the past decade or so have taught us that many of them are more interested in short‐term economic objectives than in safeguarding the natural wealth of their country for future generations”, commented David Kleijn, an ecologist and nature conservation expert at the Wageningen University, the Netherlands. “I think it is important that we now have an ambitious Biodiversity Strategy but at the same time I have little hope that we will be able to achieve its objectives”.
I think it is important that we now have an ambitious Biodiversity Strategy but at the same time I have little hope that we will be able to achieve its objectives.
There is further criticism against specific measures, such as the proposal of planting 3 billion trees. “To have lots of trees planted in an area does not necessarily translate into an increase of biodiversity. Biodiverse ecosystems are the result of million years of complex multi‐species interactions and evolutionary processes, which are not as easy to restore”, explained plant ecologist Susana Gómez‐González, from the University of Cádiz, Spain. Planting a large number of trees is a too simplistic approach for saving European forests from the combined effects of excessive anthropic pressure and climate change, and could even have detrimental effects (see Box 1). More emphasis should be placed instead in reducing tree harvesting in sensitive areas and in promoting natural forest renewal processes (Gómez‐González et al, 2020). “For a biodiversity strategy, increasing the number of trees, or even increasing the forest area, should not be an objective; priority should be given to the conservation and restoration of natural ecosystems, forests and non‐forests”, Gómez‐González said.In other cases, it could be difficult, if not impossible, to reach some of the goals because of lack of information. For example, one of the roadmap''s targets is to restore at least 25,000 km of Europe''s rivers back to free‐flowing state. However, the number of barriers dispersed along European rivers will probably prevent even getting close to the mark. An international research team has collected detailed information on existing instream barriers for 147 rivers in 36 European countries, coming up with the impressive figure of over 1.2 million obstacles that inevitably impact on river ecosystems, affecting the transport and dispersion of aquatic organisms, nutrients, and sediments (Belletti et al, 2020). Existing inventories mainly focused on dams and other large barriers, while, in fact, a large number of artificial structures are much smaller, such like weirs, locks, ramps, and fords. As a result, river fragmentation has been largely underestimated, and the models used to plan flow restoration might be seriously flawed. “To avoid ‘death by a thousand cuts’, a paradigm shift is necessary: to recognize that although large dams may draw most of the attention, it is the small barriers that collectively do most of the damage. Small is not beautiful”, concluded the authors (Belletti et al, 2020).

Box 1: Why many trees don''t (always) make a forestForests are cathedrals of biodiversity. They host by far the largest number of species on land, which provide food and essential resources for hundreds of millions of people worldwide. However, forests are disappearing and degrading at an alarming pace. The loss of these crucial ecosystems has given new impulses to a variety of projects aimed at stopping this devastation and possibly reversing the trend.Once it is gone, can you rebuild a forest? Many believe the answer is yes, and the obvious solution is to plant trees. Several countries have thus launched massive tree‐planting programs, notably India and Ethiopia, where 350 million trees have been planted in single day (https://www.unenvironment.org/news‐and‐stories/story/ethiopia‐plants‐over‐350‐million‐trees‐day‐setting‐new‐world‐record). The World Economic Forum has set up its own One Trillion Tree initiative (https://www.1t.org/) “to conserve, restore, and grow one trillion trees by 2030”. Launched in January last year at Davos, 1t.org was conceived as a platform for governments, companies and NGOs/civil society groups to support the UN Decade on Ecosystem Restoration (2021–2030). The initiative has been christened by renowned naturalist Jane Goodall, who commented: “1t.org offers innovative technologies which will serve to connect tens of thousands of small and large groups around the world that are engaged in tree planting and forest restoration”, (https://www.weforum.org/agenda/2020/01/one‐trillion‐trees‐world‐economic‐forum‐launches‐plan‐to‐help‐nature‐and‐the‐climate/).However, things are way more complicated than they appear: large‐scale tree planting schemes are rarely a viable solution and can even be harmful. “[A] large body of literature shows that even the best planned restoration projects rarely fully recover the biodiversity of intact forests, owing to a lack of sources of forest‐dependent flora and fauna in deforested landscapes, as well as degraded abiotic conditions resulting from anthropogenic activities”, commented Karen Holl from the University of Caliornia, Santa Cruz, and Pedro Brancalion from the University of São Paulo (Holl & Brancalion, 2020). A common problem of tree plantations, for example, is the low survival rate of seedlings, mostly because the wrong tree species are selected and due to poor maintenance after planting. Moreover, grasslands and savannas, which are often targeted for establishing new forests, are themselves treasure troves of biodiversity. Ending indiscriminate deforestation, improving the protection of existing forests, and promoting their restoration would therefore be a more efficient strategy to preserve biodiversity in the shorter term. If tree planting is indeed necessary, it should be well planned by selecting the right areas for reforestation, using suitable tree species that can maximize biodiversity, and involving local populations to maintain the plantations, Holl and Brancalion argue (Holl & Brancalion, 2020).

…even the best planned restoration projects rarely fully recover the biodiversity of intact forests, owing to a lack of sources of forest‐dependent flora and fauna in deforested landscapes…
The health of soil, where a high proportion of biodiversity is hosted, is another problem the new strategy should address in a more focused manner. “In my opinion, the EU Biodiversity Strategy is already a leap forward in terms of policy interest in soils in general and in soil biodiversity in particular. Compared with other nations/regions of the world, Europe is by far in the forefront regarding this issue”, commented Carlos António Guerra at the German Centre for Integrative Biodiversity Research (iDiv) in Leipzig, Germany, and Co‐leader of the Global Soil Biodiversity Observation Network (https://geobon.org/bons/thematic‐bon/soil‐bon/). “Nevertheless, the connection between soil biodiversity and ecological functions needs further commitments. Soils allow for horizontal integration of several policy agendas, from climate to agriculture and, very importantly, nature conservation. This is not explicit in the EU Biodiversity Strategy in regard to soils”. It remains to be seen if EU restoration plan will emphasize soil biodiversity, or consider it as a mere side effect of other initiatives, Guerra added. “A soil nature conservation plan should be proposed”, he said. “Only such a plan, that implies that current and future protected areas have to consider, describe and protect their soil biodiversity would make a significant push to help protect such a valuable resource”.More generally, research shows that the current paradigm of protection must be shifted to prevent further losses to biodiversity. In fact, an analysis of LIFE projects—a cornerstone of EU nature protection—found that conservation efforts are extremely polarized and strongly taxonomically biased (Mammola et al, 2020). From 1992 to 2018, investment in vertebrates was sixfold higher than that for invertebrates, with birds and mammals alone accounting for 72% of the targeted species and 75% of the total budget. In relative terms, investment per species for vertebrates has been 468 times higher than for invertebrates (Fig 4). There is no sound scientific reasoning behind this uneven conservation attention, but just popularity. “[T]he species covered by a greater number of LIFE projects were also those which attracted the most interest online, suggesting that conservation in the EU is largely driven by species charisma, rather than objective features”, the researchers wrote (Mammola et al, 2020).Open in a separate windowFigure 4Taxonomic bias in EU fauna protection effortsBreakdown of the number of projects (A) and budget allocation (B) across main animal groups covered by the LIFE projects (n = 835). (C) The most covered 30 species of vertebrates (out of 410) and invertebrates (out of 78) in the LIFE projects analyzed (n = 835). The vertical bar represents monetary investment and the blue scatter line the number of LIFE projects devoted to each species. Reproduced from (Mammola et al, 2020), with permission.  相似文献   

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Ethical challenges should be addressed before gene editing is made available to improve the immune response against emerging viruses. Subject Categories: S&S: Economics & Business, Genetics, Gene Therapy & Genetic Disease, Immunology

In 1881, Louis Pasteur proved the “germ theory of disease”, namely that microorganisms are responsible for causing a range of diseases. Following Pasteur’s and Robert Koch’s groundbreaking work on pathogens, further research during the 20th century elucidated how the immune system fends off disease‐causing microorganisms from a molecular perspective.The COVID‐19 pandemic has again focused scientific and public attention on immunology not the least owing to the race of employing vaccines to halt the spread of the virus. Although most countries have now started vaccination programs to immunize a large part of the world''s population, the process will take time, vaccines may not be available to everyone, and a number of unresolved issues remain including the potential contagiousness of vaccinated individuals and the duration of protection (Polack et al, 2020).It would therefore be extremely helpful from a public health perspective—and indeed lifesaving for those with elevated risk of developing severe course of the disease—if we could boost the human immune system by other means to better fight off SARS‐CoV‐2 and possibly other viruses. Recent studies showing that some individuals may be less susceptible to contract severe COVID‐19 depending on their genetic status support such visions (COVID‐19 Host Genetics Initiative, 2020). This could eventually inspire research projects on gene therapy with the aim of generally enhancing immunity against viral infections.
It would therefore be extremely helpful from a public health perspective […] if we could boost the human immune system by other means to better fight off SARS‐CoV‐2 …
The idea of genetically enhancing the human immune response is not new and spread from academic circles to policymakers and the general public even before the pandemic, when He Jiankui announced in November 2018 the birth of genetically edited twins who, he claimed, were resistant to HIV. The public outcry was massive, not only because He violated standards of methodological rigor and research ethics, but also because of fundamental doubts about the wisdom and legitimacy of human germline manipulation (Schleidgen et al, 2020).Somatic gene therapy has been met with a less categorical rejection, but it has also been confronted with skepticism when major setbacks or untoward events occurred, such as the death of Jesse Gelsinger during an early clinical trial for gene therapy in 1999. Nonetheless, given the drastic impact the current pandemic has on so many lives, there may be a motivation to put concerns aside. In fact, even if we managed to get rid of COVID‐19 owing to vaccines—or at least to keep its infectiousness and mortality low—another virus will appear sooner or later; an improved resistance to viral pathogens—including coronaviruses—would be an important asset.Interventions to boost the immune system could in fact make use of either germline gene editing, as has been the case of the Chinese twins, or through somatic gene editing. The first requires time and only the next generation would potentially benefit while the latter could be immediately applied and theoretically used to deal with the ongoing COVID‐19 pandemic.
Interventions to boost the immune system could in fact make use of either germline gene editing, as has been the case of the Chinese twins, or through somatic gene editing.
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Biosafety is a major challenge for developing for synthetic organisms. An early focus on application and their context could assist with the design of appropriate genetic safeguards. Subject Categories: Synthetic Biology & Biotechnology, S&S: Economics & Business

One of the goals of synthetic biology is the development of robust chassis cells for their application in medicine, agriculture, and the food, chemical and environmental industries. These cells can be streamlined by removing undesirable features and can be augmented with desirable functionalities to design an optimized organism. In a direct analogy with a car chassis, they provide the frame for different modules or “plug‐in” regulatory networks, metabolic pathways, or safety elements. In an effort to ensure a safe microbial chassis upfront, safety measures are implemented as genetic safeguards to limit risks such as unwanted cellular proliferation or horizontal gene transfer. Examples of this technology include complex genetic circuits, sophisticated metabolic dependencies (auxotrophies), and altered genomes (Schmidt & de Lorenzo, 2016; Asin‐Garcia et al, 2020). Much like seat belts or airbags in cars, these built‐in measures increase the safety of the chassis and of any organisms derived from it. Indeed, when it comes to safety, synthetic biology can still learn from a century‐old technology such as cars about the significance of context for the development of biosafety technologies.Every car today has seat belts installed by default. Yet, seat belts were not always a standard component; in fact, they were not even designed for cars to begin with. The original 2‐point belts were first used in aviation and only slowly introduced for motorized vehicles. Only after some redesign, the now‐common 3‐point car seat belts would become the life‐saving equipment that they are today. A proper understanding of the context of their application was therefore one of the crucial factors for their success and wide adoption. Context matters: It provides meaning for and defines what a technological application is best suited for. What was true for seat belts may be also true for biosafety technologies such as genetic safeguards.
… when it comes to safety, synthetic biology can still learn from a century‐old technology such as cars about the significance of context for the development of biosafety technologies.
Society has a much higher awareness of technology’s risks compared to the early days of cars. Society today requires that technological risks are anticipated and assessed before an innovation or its applications are widely deployed. In addition, society increasingly demands that research and innovation take into account societal needs and values. This has led to, among others, the Responsible Research and Innovation (RRI; von Schomberg, 2013) concept that has become prominent in European science policy. In a nutshell, RRI requires that innovative products and processes align with societal needs, expectations, and values in consultation with stakeholders. RRI and similar frameworks suggest that synthetic biology must anticipate and respond not only to risks, but also to societal views that frame its evaluation and risk assessment.  相似文献   

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Even if the predominant model of science communication with the public is now based on dialogue, many experts still adhere to the outdated deficit model of informing the public. Subject Categories: Genetics, Gene Therapy & Genetic Disease, S&S: History & Philosophy of Science, S&S: Ethics

During the past decades, public communication of science has undergone profound changes: from policy‐driven to policy‐informing, from promoting science to interpreting science, and from dissemination to interaction (Burgess, 2014). These shifts in communication paradigms have an impact on what is expected from scientists who engage in public communication: they should be seen as fellow citizens rather than experts whose task is to increase scientific literacy of the lay public. Many scientists engage in science communication, because they see this as their responsibility toward society (Loroño‐Leturiondo & Davies, 2018). Yet, a significant proportion of researchers still “view public engagement as an activity of talking to rather than with the public” (Hamlyn et al, 2015). The highly criticized “deficit model” that sees the role of experts as educating the public to mitigate skepticism still persists (Simis et al, 2016; Suldovsky, 2016).Indeed, a survey we conducted among experts in training seems to corroborate the persistence of the deficit model even among younger scientists. Based on these results and our own experience with organizing public dialogues about human germline gene editing (Box 1), we discuss the implications of this outdated science communication model and an alternative model of public engagement, that aims to align science with the needs and values of the public.Box 1

The DNA‐dialogue project

The Dutch DNA‐dialogue project invited citizens to discuss and form opinions about human germline gene editing. During 2019 and 2020, this project organized twenty‐seven dialogues with professionals, such as embryologists and midwives, and various lay audiences. Different scenarios of a world in 2039 (https://www.rathenau.nl/en/making‐perfect‐lives/discussing‐modification‐heritable‐dna‐embryos) served as the starting point. Participants expressed their initial reactions to these scenarios with emotion‐cards and thereby explored the values they themselves and other participants deemed important as they elaborated further. Starting each dialogue in this way provides a context that enables everyone to participate in dialogue about complex topics such as human germline gene editing and demonstrates that scientific knowledge should not be a prerequisite to participate.An important example of “different” relevant knowledge surfaced during a dialogue with children between 8 and 12 years in the Sophia Children’s Hospital in Rotterdam (Fig 1). Most adults in the DNA‐dialogues accepted human germline gene modification for severe genetic diseases, as they wished the best possible care and outcome for their children. The children at Sophia, however, stated that they would find it terrible if their parents had altered something about them before they had been born; their parents would not even have known them. Some children went so far to say they would no longer be themselves without their genetic condition, and that their condition had also given them experiences they would rather not have missed.Open in a separate windowFigure 1 Children participating in a DNA‐dialogue meeting. Photographed by Levien Willemse.  相似文献   

10.
A survey of academics in Germany shows a lack of and a great demand for training in leadership skills. Subject Categories: Careers, Science Policy & Publishing

Success and productivity in science is measured largely by the number of publications in scientific journals and the acquisition of third‐party funding to finance further research (Detsky, 2011). Consequently, as young researchers advance in their careers, they become highly trained in directly related skills, such as scientific writing, so as to increase their chances in securing publications and grants. Acquiring leadership skills, however, is often neglected as these do not contribute to the evaluation of scientific success (Detsky, 2011). Therefore, an early‐career researcher may become leader of a research group based on publication record and solicitation of third‐party funding, but without any training of leadership or team management skills (Lashuel, 2020). Leadership, in the context of academic research, requires a unique list of competencies, knowledge and skills in addition to “traditional” leadership skills (Anthony & Antony, 2017), such as managing change, adaptability, empathy, motivating individuals, and setting direction and vision among others. Academic leadership also requires promoting the research group’s reputation, networking, protecting staff autonomy, promoting academic credibility, and managing complexity (Anthony & Antony, 2017).  相似文献   

11.
Research needs a balance of risk‐taking in “breakthrough projects” and gradual progress. For building a sustainable knowledge base, it is indispensable to provide support for both. Subject Categories: Careers, Economics, Law & Politics, Science Policy & Publishing

Science is about venturing into the unknown to find unexpected insights and establish new knowledge. Increasingly, academic institutions and funding agencies such as the European Research Council (ERC) explicitly encourage and support scientists to foster risky and hopefully ground‐breaking research. Such incentives are important and have been greatly appreciated by the scientific community. However, the success of the ERC has had its downsides, as other actors in the funding ecosystem have adopted the ERC’s focus on “breakthrough science” and respective notions of scientific excellence. We argue that these tendencies are concerning since disruptive breakthrough innovation is not the only form of innovation in research. While continuous, gradual innovation is often taken for granted, it could become endangered in a research and funding ecosystem that places ever higher value on breakthrough science. This is problematic since, paradoxically, breakthrough potential in science builds on gradual innovation. If the value of gradual innovation is not better recognized, the potential for breakthrough innovation may well be stifled.
While continuous, gradual innovation is often taken for granted, it could become endangered in a research and funding ecosystem that places ever higher value on breakthrough science.
Concerns that the hypercompetitive dynamics of the current scientific system may impede rather than spur innovative research have been voiced for many years (Alberts et al, 2014). As performance indicators continue to play a central role for promotions and grants, researchers are under pressure to publish extensively, quickly, and preferably in high‐ranking journals (Burrows, 2012). These dynamics increase the risk of mental health issues among scientists (Jaremka et al, 2020), dis‐incentivise relevant and important work (Benedictus et al, 2016), decrease the quality of scientific papers (Sarewitz, 2016) and induce conservative and short‐term thinking rather than risk‐taking and original thinking required for scientific innovation (Alberts et al, 2014; Fochler et al, 2016). Against this background, strong incentives for fostering innovative and daring research are indispensable.  相似文献   

12.

Recent cryo‐EM‐based models reveal how the ER membrane protein complex may accomplish insertion of protein transmembrane domains with limited hydrophobicity.

Insertion of strongly hydrophobic TMDs into the ER membrane is mediated by the Sec61 complex for co‐translational insertion and the GET complex for post‐translational insertion of tail‐anchors (Volkmar & Christianson, 2020). By contrast, the EMC inserts TMDs of limited hydrophobicity, frequently located at the N‐ or C‐termini of proteins, and is involved in biogenesis of multi‐spanning membrane proteins (Volkmar & Christianson, 2020).The EMC is highly conserved (Wideman, 2015). In vertebrates, ten subunits have been identified (EMC1‐10), two of which, EMC8 and EMC9, are homologous and the result of a vertebrate‐specific gene duplication (Wideman, 2015). In Saccharomyces cerevisiae, EMC8 has been lost (Wideman, 2015). Only EMC3 displays clear homology to other membrane protein insertases, the Oxa1 family (Wideman, 2015; Volkmar & Christianson, 2020). This family includes YidC, which inserts TMDs into the bacterial cytoplasmic membrane, usually in cooperation with the Sec61‐homologous SecYEG channel (Volkmar & Christianson, 2020). Their association, along with the SecDF ancillary complex, forms a holo‐translocon capable of protein secretion and TMD insertion, with striking similarities to the EMC complex (Martin et al, 2019).Recent work by Pleiner et al (2020) presented a 3.4 Å cryo‐EM structure of the human EMC purified via a GFP‐tag on EMC2 and incorporated into a phospholipid nanodisc. The complex is formed by nine proteins (EMC1‐8, EMC10) (Pleiner et al, 2020). EMC8 and EMC9 are structurally similar, and their association with EMC2 is mutually exclusive (O''Donnell et al, 2020). Of the 12 TMDs, nine constitute the pseudosymmetric central ordered core, with a basket‐shaped cytosolic vestibule formed primarily by alpha‐helices of the EMC3 and EMC6 TMDs and cytosolic EMC2 (Fig 1A; Pleiner et al, 2020). The L‐shaped lumenal domain of the EMC consists mostly of beta‐sheets (Fig 1A; Pleiner et al, 2020), flanked by a conspicuous and conserved amphipathic alpha‐helix of EMC1 sealing the vestibule at the interface between the membrane and the ER lumen, together with another smaller amphipathic helix contributed by EMC3 (Fig 1A; Pleiner et al, 2020). In the ER lumen, the two 8‐bladed propellers of EMC1 contact six of the eight other subunits and stabilize the entire complex (Fig 1A; Pleiner et al, 2020). Beta‐sandwiches of EMC7 and EMC10 are anchored to the EMC1 lumenal domain (Fig 1A; Pleiner et al, 2020). In the cytosol, the tetratricopeptide repeat (TPR) spiral of EMC2 forms a cup underneath the partially hydrophilic vestibule in the membrane between the TMDs of EMC3 and EMC6, bridging the cytosolic ends of TMDs of EMC1, 3 and 5 (Fig 1A; Pleiner et al, 2020). Cytosolic EMC8 is bound to the opposite face of EMC2 (Fig 1A).Open in a separate windowFigure 1Comparison of the structures of human and yeast EMC(A) Cryo‐EM 3D map of the human (emdb‐21929) and yeast (emdb‐21587) EMC, showing front and back views with individual subunits coloured. Membrane position, obtained from the OPM database, is shown by grey discs. (B) Close‐up view of the EMC cavity formed by EMC3 and EMC6. Left, shown in a hydrophobicity surface pattern. Right, surface representation overlapped with the TMDs of EMC3 and EMC6. EMC4, flexible and with a gate function at the substrate‐binding place, is shown in pink in the yeast representation. EMC4 is not visible at the atomic EMC human structure, although is observed as a weak density at the human model, accompanied by TMs of EMC7 and EMC10 (Pleiner et al, 2020). (C) The yeast EMC following > 5 µs of CG‐MD simulation. The protein is shown as surface and coloured as per Pleiner et al (2020). The computed densities of waters and phospholipid tails and phosphates are shown as blue, yellow and lime green densities, sliced to bisect the cavity for clarity. Right, inset of the EMC cavity. Methods: CG‐MD simulations were built using PDB 6WB9 in a solvated symmetric POPC/POPE/cholesterol membrane and run in the Martini forcefield as described in Martin et al (2019). 3 µs unrestrained simulations were run, followed by 2.5 µs backbone restrained simulation for density calculation, done using VolMap in VMD (Humphrey et al, 1996).The 3.0 Å cryo‐EM structure of the yeast EMC presented by Bai and colleagues shows a very similar overall organization (Bai et al, 2020). Here, purification was via a 3xFLAG‐tag on EMC5, and the structure of the 8‐subunit complex (without EMC8/9) was visualized in detergent solution (Bai et al, 2020). The yeast complex has twelve TMDs like the human EMC, but unlike the human structure, EMC4 in yeast has three TMDs that are clearly visible (Bai et al, 2020). They are angled in the membrane pointing away from the complex at the cytosolic end (Fig 1A), and Bai et al (2020) propose that TMDs of EMC4, EMC3 and EMC6 form a substrate‐binding pocket similar to that of YidC. As in the human EMC, there are two amphipathic helices (EMC1 and EMC3) at the membrane/lumen interface (Fig 1A; Bai et al, 2020). In the ER lumen, yeast EMC1 only has one 8‐bladed beta‐propeller, to which the beta‐sandwiches of EMC7 and EMC10 are anchored (Fig 1A; Bai et al, 2020). In the cytosol, EMC2 bridges EMC3, 4 and 5, and its TPR repeats form a cup underneath the vestibule similar to human EMC2 (Fig 1A; Bai et al, 2020).The authors propose that insertion of a partially hydrophilic TMD by the yeast EMC is mechanistically similar to insertion by bacterial YidC (Bai et al, 2020). Yeast EMC is proposed to bind substrate between TMD2 of EMC3 and TMD2 of EMC4 in a pocket with polar and positively charged amino acids at either end and hydrophobic amino acids in the centre (Fig 1B; Bai et al, 2020). Much has been made of a conserved positive region within the EMC complex here, present in an equivalent position also in YidC (Kumazaki et al, 2014): It is claimed to be important for the incorporation of more‐hydrophilic TMDs and perhaps responsible for the “positive‐inside” orientation rule (von Heijne, 1992). Yeast and human EMC3 contain a specific R31 and R26 residue, respectively, conserved also in YidC and important for function of the EMC, as well as for YidC in Gram‐positive, but interestingly not Gram‐negative, bacteria (Chen et al, 2014; Pleiner et al, 2020; Bai et al, 2020). Another interesting feature, also conserved with YidC, is the flexibility of the TMDs flanking the substrate‐binding pocket, critical for EMC entry of substrates (Bai et al, 2020).In the human EMC, methionine residues in a cytosolic loop of EMC3 act as a substrate bait (Pleiner et al, 2020). Polar and charged residues within the substrate‐binding groove guide the lumenal domain across the membrane, facilitated by local membrane thinning (Pleiner et al, 2020; Fig 1B). The positive charges within the substrate‐binding site exclude signal peptides and enforce the “positive‐inside rule” (von Heijne, 1992; Pleiner et al, 2020). Flexible TMDs of EMC4, EMC7 and EMC10 forming a “lateral gate” of the substrate‐binding groove allow sampling of the bilayer by the substrate TMD (Pleiner et al, 2020). As the shortened TMDs of EMC3 and EMC6 cannot stably bind the substrate TMD, they favour its release into the bilayer (Pleiner et al, 2020). The EMC1 beta‐propeller(s) may recruit additional protein maturation factors in the ER lumen (Pleiner et al, 2020; Bai et al, 2020) or bind the Sec61 channel to allow cooperation between the two insertases (Bai et al, 2020).Arguably, the most interesting feature of the EMC complex is the location of a large interior cavity with distinctive hydrophilic character, which likely aids TMD insertion (Fig 1B). We ran a coarse‐grained molecular dynamics (CG‐MD) simulation of the yeast EMC structure, which highlights a profound perturbation of the phospholipid bilayer in the EMC interior cavity (Fig 1C). Here, a deep gorge forms in the cytoplasmic leaflet of the bilayer, allowing the cavity to become flooded with water (Fig 1C). Note the location of the lipid head groups here (lime green), which presumably define the site of amphipathic TMD insertion. The incursion of phospholipids into the centre of the EMC complex is a feature shared by the bacterial holo‐translocon (Martin et al, 2019) and perhaps by all membrane protein insertases. The shape and character of the EMC cavity presumably dictate its predisposition for less hydrophobic TMDs; it would be interesting to see whether the cavities of different insertases are similarly tailored to suit their substrates.  相似文献   

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Understanding the mechanisms by which natural anti‐freeze proteins protect cells and tissues from cold could help to improve the availability of donor organs for transplantation.

The first successful organ transplant in humans was performed in 1954 by Joseph Murray, who used a patient’s twin as a kidney donor. Murrays’ breakthrough paved the way for organ transplantation and the number of transplanted organs has grown ever since. For example, in 2017, a total of 139.024 solid organs—mostly kidney, liver, heart, lung, pancreas, and small bowel—were transplanted (Fig 1A). But this number only reflects 10% of the worldwide need; many patients still die of end‐stage organ failure while on a waiting list. The limited number of donor organs contributes only partially to this shortage. Many donor organs are not transplanted eventually owing to inefficient preservation techniques that shorten their extracorporeal lifetime. In fact, the percentage of donor organs that are unused is estimated to range from around 25% for kidneys and livers up to 70–80% for hearts and lungs (Giwa et al, 2017); Fig 1B).Open in a separate windowFigure 1Organ transplantation and preservability statusStatistics show a positive correlation between the duration of ex vivo preservation and the number of organ transplants. Number of solid organs transplanted in 2017 (A). Percentage of organs failed to be transplanted (B). Duration of solid organ ex vivo preservation in static cold storage (C). Sources: Data from the Global Observatory on Donation and Transplantation and (Parsons et al, 2014), (Guibert et al, 2011) and (Editorial: Buying time for transplants (2017))
Many donor organs are not transplanted eventually owing to inefficient preservation techniques that shorten their extracorporeal lifetime.
To address the shortage of donor organs and decrease the number of organs that go to waste, biobanks could efficiently store viable tissues and organs until transplantation. Yet, the current standard for ex vivo preservation of donor organs is static cold storage (4–8°C) which, depending on the organ, ensures viable conservation for only some hours; hearts are typically viable for a maximum of only 4 h (Fig 1C). In addition, this approach leads to hypothermic damage and to ischemia/reperfusion injury.Hence, there is an urgent need for strategies that prolong the viable preservation of donor organs. Two main strategies have emerged for cryopreservation and subzero storage, both of which cool tissues below the freezing point. While subzero storage just below 0°C may suffice for short‐term preservation, cryopreservation at −80°C or even lower temperatures is required for long‐term storage in biobanks. A proof‐of‐principle study already demonstrated that subzero preservation extended the preservation of rat hearts up to 24 h after collection (Amir et al, 2004); cryopreservation of whole hearts is currently not possible. The main reason is that lowering the temperature below the freezing point of water leads to ice formation, which causes cell damage and destroys tissues. One of the main challenges in biomedical research for organ transplantation is therefore finding non‐toxic and biocompatible antifreeze compounds that enable subzero storage and cryopreservation without causing tissue damage. An additional benefit is a larger time window to perform evaluation in terms of organ size and human leukocyte antigens matching and preparing the recipient patient to increase the chance of a successful transplantation.  相似文献   

15.
Segregation of the largely non‐homologous X and Y sex chromosomes during male meiosis is not a trivial task, because their pairing, synapsis, and crossover formation are restricted to a tiny region of homology, the pseudoautosomal region. In humans, meiotic X‐Y missegregation can lead to 47, XXY offspring, also known as Klinefelter syndrome, but to what extent genetic factors predispose to paternal sex chromosome aneuploidy has remained elusive. In this issue, Liu et al (2021) provide evidence that deleterious mutations in the USP26 gene constitute one such factor.Subject Categories: Cell Cycle, Development & Differentiation, Molecular Biology of Disease

Analyses of Klinefelter syndrome patients and Usp26‐deficient mice have revealed a genetic influence on age‐dependent sex chromosome missegregation during male meiosis.

Multilayered mechanisms have evolved to ensure successful X‐Y recombination, as a prerequisite for subsequent normal chromosome segregation. These include a distinct chromatin structure as well as specialized proteins on the pseudoautosomal region (Kauppi et al, 2011; Acquaviva et al, 2020). Even so, X‐Y recombination fails fairly often, especially in the face of even modest meiotic perturbations. It is perhaps not surprising then that X‐Y aneuploidy—but not autosomal aneuploidy—in sperm increases with age (Lowe et al, 2001; Arnedo et al, 2006), as does the risk of fathering sons with Klinefelter syndrome (De Souza & Morris, 2010).Klinefelter syndrome is one of the most common aneuploidies in liveborn individuals (Thomas & Hassold, 2003). While most human trisomies result from errors in maternal chromosome segregation, this is not the case for Klinefelter syndrome, where the extra X chromosome is equally likely to be of maternal or paternal origin (Thomas & Hassold, 2003; Arnedo et al, 2006). Little is known about genetic factors in humans that predispose to paternal XY aneuploidy, i.e., that increase the risk of fathering Klinefelter syndrome offspring. The general notion has been that paternally derived Klinefelter syndrome arises stochastically. However, fathers of Klinefelter syndrome patients have elevated rates of XY aneuploid sperm (Lowe et al, 2001; Arnedo et al, 2006), implying a persistent defect in spermatogenesis in these individuals rather than a one‐off meiotic error.To identify possible genetic factors contributing to Klinefelter syndrome risk, Liu et al (2021) performed whole‐exome sequencing in a discovery cohort of > 100 Klinefelter syndrome patients, followed by targeted sequencing in a much larger cohort of patients and controls, as well as Klinefelter syndrome family trios. The authors homed in on a mutational cluster (“mutated haplotype”) in ubiquitin‐specific protease 26 (USP26), a testis‐expressed gene located on the X chromosome. Effects of this gene’s loss of function (Usp26‐deficient mice) on spermatogenesis have recently been independently reported by several laboratories and ranged from no detectable fertility phenotype (Felipe‐Medina et al, 2019) to subfertility/sterility associated with both meiotic and spermiogenic defects (Sakai et al, 2019; Tian et al, 2019). With their Klinefelter syndrome cohort findings, Liu et al (2021) also turned to Usp26 null mice, paying particular attention to X‐Y chromosome behavior and—unlike earlier mouse studies—including older mice in their analyses. They found that Usp26‐deficient animals often failed to achieve stable pairing and synapsis of X‐Y chromosomes in spermatocytes, produced XY aneuploid sperm at an abnormally high frequency, and sometimes also sired XXY offspring. Importantly, these phenotypes only occurred at an advanced age: XY aneuploidy was seen in six‐month‐old, but not two‐month‐old Usp26‐deficient males. Moreover, levels of spindle assembly checkpoint (SAC) proteins also reduced in six‐month‐old males. Thus, in older Usp26 null mice, the combination of less efficient X‐Y pairing and less stringent SAC‐mediated surveillance of faithful chromosome segregation allows for sperm aneuploidy, providing another example of SAC leakiness in males (see Lane & Kauppi, 2019 for discussion).Liu et al’s analyses shed some light on what molecular mechanisms may be responsible for the reduced efficiency of X‐Y pairing and synapsis in Usp26‐deficient spermatocytes. USP26 codes for a deubiquitinating enzyme that has several substrates in the testis. Because USP26 prevents degradation of these substrates, their levels should be downregulated in Usp26 null testes. Liu et al (2021) show that USP26 interacts with TEX11, a protein required for stable pairing and normal segregation of the X and Y chromosomes in mouse meiosis (Adelman & Petrini, 2008). USP26 can de‐ubiquitinate TEX11 in vitro, and in Usp26 null testes, TEX11 was almost undetectable. It is worth noting that USP26 has several other known substrates, including the androgen receptor (AR), and therefore, USP26 disruption likely contributes to compromised spermatogenesis via multiple mechanisms. For example, AR signaling‐dependent hormone levels are misregulated in Usp26 null mice (Tian et al, 2019).The sex chromosome phenotypes observed in Usp26 null mice predict that men with USP26 mutations may be fertile, but producing XY aneuploid sperm at an abnormally high frequency, and that spermatogenic defects should increase with age (Fig 1). These predictions were testable, because the mutated USP26 haplotype, present in 13% of Klinefelter syndrome patients, was reasonably common also in fertile men (7–10%). Indeed, sperm XY aneuploidy was substantially higher in fertile men with the mutated USP26 haplotype than in those without USP26 mutations. Some mutation carriers produced > 4% aneuploid sperm. Moreover, age‐dependent oligospermia was also found associated with the mutated USP26 haplotype.Open in a separate windowFigure 1Mutated USP26 as genetic risk factor for age‐dependent X‐Y defects in spermatogenesisMouse genetics demonstrate that deleterious USP26 mutations lead to less‐efficient X‐Y pairing and recombination with advancing age. Concomitant decrease of spindle assembly checkpoint (SAC) protein levels leads to less‐efficient elimination of metaphase I spermatocytes that contain misaligned X and Y chromosomes. This allows for the formation of XY aneuploid sperm in older individuals and subsequently increased age‐dependent risk for fathering Klinefelter syndrome (KS) offspring, two correlates also observed in human USP26 mutation carriers. At the same time, oligospermia/subfertility also increases with advanced age in both Usp26‐deficient mice and USP26 mutation‐carrying men, tempering Klinefelter syndrome offspring risk but also decreasing fecundity.As indicated by its prevalence in the normal control population, the USP26 mutated haplotype is not selected against in the human population. With > 95% of sperm in USP26 mutation carriers having normal haploid chromosomal composition, the risk of producing (infertile) Klinefelter syndrome offspring remains modest, likely explaining why USP26 mutant alleles are not eliminated. Given that full Usp26 disruption barely affects fertility of male mice during their prime reproductive age (Felipe‐Medina et al, 2019; Tian et al, 2019; Liu et al, 2021), there is little reason to assume strong negative selection against USP26 variants in humans. USP26 as the first‐ever genetic risk factor predisposing to sperm X‐Y aneuploidy and paternal origin Klinefelter syndrome offspring in humans, as uncovered by Liu et al, may be just one of many. 90% of Liu et al’s Klinefelter syndrome cases were not associated with USP26 mutations. But even in the age of genomics, discovery of Klinefelter syndrome risk factors is not straightforward, since most sperm of risk mutation carriers will not be XY aneuploid and thus not give rise to Klinefelter syndrome offspring. In addition, as Usp26 null mice demonstrate, both genetic and non‐genetic modifiers impact on penetrance of the XY aneuploidy phenotype: Spermatogenesis in the absence of Usp26 was impaired in the DBA/2 but not the C57BL/6 mouse strain background (Sakai et al, 2019), and in older mice, there was substantial inter‐individual variation in the severity of the X‐Y defect (Liu et al, 2021). In human cohorts, genetic and non‐genetic modifiers are expected to blur the picture even more.Future identification of sex chromosome aneuploidy risk factors has human health implications beyond Klinefelter syndrome. Firstly, XXY incidence is not only relevant for Klinefelter syndrome livebirths—it also contributes to stillbirths and spontaneous abortions, at a 4‐fold higher rate than to livebirths (Thomas & Hassold, 2003). Secondly, persistent meiotic X‐Y defects can, over time, result in oligospermia and even infertility. Since the mean age of first‐time fathers is steadily rising and currently well over 30 years in many Western countries, age‐dependent spermatogenic defects will be of ever‐increasing clinical relevance.  相似文献   

16.
Many scientists, confined to home office by COVID‐19, have been gathering in online communities, which could become viable alternatives to physical meetings and conferences. Subject Categories: S&S: Careers & Training, Methods & Resources, S&S: Ethics

As COVID‐19 has brought work and travel to a grinding halt, scientists explored new ways to connect with each other. For the gene regulation community, this started with a Tweet that quickly expanded into the “Fragile Nucleosome” online forum, a popular seminar series, and many intimate discussions connecting scientists all over the world. More than 2,500 people from over 45 countries have attended our seminars so far and our forum currently has ~ 1,000 members who have kick‐started discussion groups and mentorship opportunities. Here we discuss our experience with setting up the Fragile Nucleosome seminars and online discussion forum, and present the tools to enable others to do the same.Too often, we forget the importance of social interactions in science. Indeed, many creative ideas originated from impromptu and fortuitous encounters with peers, in passing, over lunch, or during a conference coffee break. Now, the ongoing COVID‐19 crisis means prolonged isolation, odd working hours, and less social interactions for most scientists confined to home. This motivated us to create the “Fragile Nucleosome” virtual community for our colleagues in the chromatin and gene regulation field.
… the ongoing COVID‐19 crisis means prolonged isolation, odd working hours and less social interactions for most scientists confined to home.
While the need to address the void created by the COVID‐19 pandemic triggered our actions, a large part of the international community already has had limited access to research networks in our field. Our initiative offered new opportunities though, in particular for those who have not benefited from extensive networks, showing how virtual communities can address disparities in accessibility. This should not be a stop‐gap measure during the pandemic: Once we come out from our isolation, we still need to address the drawbacks of in‐person scientific conferences/seminars, such as economic disparities, travel inaccessibility, and overlapping family responsibilities (Sarabipour, 2020). Our virtual community offers some solutions to the standing challenges (Levine & Rathmell, 2020), and we hope our commentary can help start conversations about the advantages of virtual communities in a post‐pandemic world.
… once we come out from our isolation we still need to address the drawbacks of in‐person scientific conferences/seminars, such as economic disparities, travel inaccessibility and overlapping family responsibilities…
  相似文献   

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Lessons from implementing quality control systems in an academic research consortium to improve Good Scientific Practice and reproducibility. Subject Categories: Microbiology, Virology & Host Pathogen Interaction, Science Policy & Publishing

Low reproducibility rates within biomedical research negatively impact productivity and translation. One promising approach to enhance the transfer of robust results from preclinical research into clinically relevant and transferable data is the systematic implementation of quality measures in daily laboratory routines.
Although many universities expect their scientists to adhere to GSPs, they often neither systematically support, nor monitor the quality of their research activities.
Today''s fast‐evolving research environment needs effective quality measures to ensure reproducibility and data integrity (Macleod et al, 2014; Begley et al, 2015; Begley & Ioannidis, 2015; Baker, 2016). Academic research institutions and laboratories may be as committed to good scientific practices (GSPs) as their counterparts in the biotech and pharmaceutical industry but operate largely without clearly defined standards (Bespalov et al, 2021; Emmerich et al, 2021). Although many universities expect their scientists to adhere to GSPs, they often neither systematically support, nor monitor the quality of their research activities. Peer review of publications is still regarded as the primary validation of quality control in academic research. However, reviewers only assess work after it has been performed—often over years—and interventions in the experimental process are thus no longer possible.The reasons for the lack of dedicated quality management (QM) implementations in academic laboratories include an anticipated overload of regulatory tasks that could negatively affect productivity, concerns about the loss of scientific freedom, and importantly, limited resources in academia and academic funding schemes.  相似文献   

19.
While there is growing evidence that perturbation of the gut microbiota can result in a variety of pathologies including gut tumorigenesis, the influence of commensal fungi remains less clear. In this issue, Zhu et al (2021) show that mycobiota dysbiosis stimulates energy metabolism changes in subepithelial macrophages promoting colon cancer via enhancing innate lymphoid cell activity. These findings provide insights into a role of the gut flora in intestinal carcinogenesis and suggest opportunities for adjunctive antifungal or immunotherapeutic strategies to prevent colorectal cancer.Subject Categories: Cancer, Immunology, Metabolism

Recent work reports a role for the commensal gut flora in driving aberrant host immunity and malignant cytokine signaling.

There is growing evidence for an important role for the microbiota in influencing tumorigenesis (Helmink et al, 2019). It is now well documented that gut microbiota represents a highly diverse polymicrobial population of bacteria, fungi, viruses, and protozoa. Recent evidence highlights involvement of the bacterial component of the gut microbiota in protection or enhancement of colorectal tumorigenesis. In contrast, the importance of the mycobiota is less well understood although recently suggested to promote pancreatic oncogenesis and colitis‐associated colon cancer (CAC) (Wang et al, 2018; Aykut et al, 2019). Therefore, gut fungi may play a role in the development of other gastro‐intestinal cancer types, such as CRC. Notably, there is emerging evidence suggesting that mycobiota imbalance modulates immune cells and can trigger inflammatory bowel disease (IBD) (Richard & Sokol, 2019).Here, Zhu et al (2021) provide new insight into the association between mycobiota dysbiosis, immunomodulation, and tumorigenesis in the mouse gut (Fig 1).Open in a separate windowFigure 1Dectin‐3 deficiency induces fungal dysbiosis and tumorigenesis in mice by orchestrating immune cell metabolism and cytokine signalingIn the gut of wild‐type mice, the natural population of the commensal yeast Candida albicans is detected by the Dectin‐3 receptor located on the subepithelial macrophage cell surface. This recognition allows macrophages to maintain gut homeostasis by exerting an antifungal activity. In Dectin‐3‐deficient mice, the mycobiota becomes disrupted and aberrantly increased populations of C. albicans emerge. Elevated C. albicans load triggers increased glycolysis in macrophages and interleukin‐7 (IL‐7) secretion. Macrophage‐derived IL‐7 finally induces IL‐22 secretion by group‐3 innate lymphoid cells that in turn promote tumor cell proliferation in the gut epithelium.The current study (Zhu et al, 2021) is based on previous observations suggesting that human pathogenic fungi are recognized by the C‐type lectin receptor Dectin‐3. This led Zhu et al (2021) to test whether the mycobiota influenced gut tumor formation and is linked to immune recognition mediated by Dectin‐3. First, the authors demonstrated that mice lacking the Dectin‐3 receptor had increased colonic tumorigenesis in response to the azoxymethane (AOM) and dextran sodium sulfate (DSS). This was evident histologically in marked differences in tumor number, size, and burden in Dectin‐3‐deficient mice. Of note, immunohistochemical staining revealed that the lack of Dectin‐3 induced gut tumor formation by triggering epithelial cell proliferation rather than preventing cell apoptosis. In fact, first insight into the impact of microbes in CAC was suggested by the observation that co‐housed WT and Dectin‐3‐deficient mice displayed no difference in tumorigenesis. The pivotal role of the microbiota was then underlined in fecal transplantation experiments. Chemically induced germ‐free mice that received feces from Dectin‐3 tumor‐bearing mice displayed exacerbated tumor development compared to wild‐type controls. In addition, the fungal burden was specifically increased in tumor‐bearing Dectin‐3‐deficient animals. Deep profiling of the mycobiota alterations demonstrated an increase in a single yeast species, i.e., Candida albicans, that normally behaves as commensal in the gut (Papon et al, 2013; Wilson, 2019). Preliminary experiments suggested that the increased burden of C. albicans in Dectin‐3‐deficient tumor‐bearing mice is due to impaired antifungal killing by macrophages. Consistently, elevated C. albicans populations triggered glycolysis and inflammatory IL‐7 secretion from lamina propria macrophages, suggesting that Dectin‐3 deficiency‐induced fungal dysbiosis resulted in modulation of gut macrophage metabolism, promoting tumorigenesis. Exploring the molecular and cellular mechanisms that linked macrophage‐derived IL‐7 secretion and CRC development, Zhu et al (2021) showed in vitro that IL‐7 produced by subepithelial macrophages induced IL‐22 secretion by group‐3 innate lymphoid cells (ILC3s). In turn, up‐regulation of IL‐22 in Dectin‐3‐deficient mice contributed to the oncogenesis seen in these animals. Finally, a detailed analysis of tumor tissues collected from 172 patients with CRC showed correlation and poorer clinical outcome in patients with decreased expression of Dectin‐3, but increased expression of IL‐22 and mycobiota burden, although they did not directly link this to the presence of C. albicans in these patients.Overall, Zhu et al (2021) define a new cell paradigm linking mycobiota dysbiosis, macrophage energy metabolism, and innate lymphoid cell function to tumor development in the mouse gut. In this context, this study also sheds additional light on a new role of ILC3s, a recently described type of lymphoid effectors (Serafini et al, 2015). Indeed, ILC3s have been shown in the present article to act as cornerstone cells orchestrating cytokine‐regulated tumorigenesis in the gut. Beyond these pathophysiological considerations, the study opens up new opportunities for developing adjunctive antifungal or immunotherapeutic strategies for the prevention of high morbidity in CRC. Importantly, this enlightening article provides firm evidence that colonic C. albicans populations promote metabolic reprogramming in lamina propria macrophages and tumor cell formation. Metabolic reprogramming has been observed with other fungi, such as Aspergillus fumigatus, which induces metabolic rewiring of alveolar macrophages in the lung epithelium (Gonçalves et al, 2020). In line, the report by Zhu et al (2021) adds to previous work suggesting that mycobiota promotes pancreatic oncogenesis via activation of mannose‐binding lectins (Aykut et al, 2019). Mycobiota dysbiosis therefore stands out as an important new field of investigation in cancer research that is ripe for future exploration.  相似文献   

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