Awakening the genome

Fertilization of an egg by sperm is the beginning of new life. The maternal and paternal genetic information, that collectively store the body plan of the living being, are combined after fertilization. However, the DNA is still in an inactive state in the cell nucleus at this early stage of life. While the first division of the fertilized egg cell functions with the help of maternal factors stored in the egg, for further development of an embryo the synthesis of new embryonic products is necessary, which requires access to the DNA of the embryo. As shown in Science, Kikuë Tachibana and her team at the MPI of Biochemistry have now shown that pioneer factor Nr5a2 awakens the embryonic DNA.

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Attack via byways

Increased cell proliferation is a key feature of diseases such as cancer. A research team from the University of Würzburg and two Leibniz Institutes has now succeeded in indirectly influencing this process.

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The beta cell whisperer gene

Researchers from Dresden, together with Danish and Finnish colleagues, identify a gene that enables beta cells to communicate with each other, helping the pancreas to respond to glucose by insulin secretion.

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Node-centric expression models (NCEMs): Graph-neural networks reveal communication between cells

How do single cells communicate in a tissue? How can these interactions be modeled, while retaining information of spatial context? Researchers around Fabian Theis from Helmholtz Munich Computational Health Center and Technical University of Munich (TUM) have generated a new method to represent cell communication: the node-centric expression models (NCEM). These models are based on graph neural networks and helps to uncover the effects of cell tissue niche composition on gene expression without loss of spatial information.

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New factor in the development of hereditary kidney cancer discovered

Scientists have identified the loss of the protein HIRA (histone cell cycle regulator) as a possible driving factor in a highly metastatic form of kidney cancer / study in ‘Science Advances’ opens up new perspectives for targeted therapies

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Infection research: Antibodies prevent cell infection

Using bacteria of the Bartonella henselae species, researchers from Goethe University, Frankfurt University Hospital, the Paul Ehrlich Federal Institute for Vaccines and Biomedicines in Langen, and the University of Oslo demonstrated for the first time that antibodies can prevent certain surface proteins of bacterial pathogens from entering host cells. The findings are important for the development of new drugs against highly resistant infectious agents.

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Microbial enzymes are the key to pectin digestion in leaf beetles

A research team at the Max Planck Institute for Chemical Ecology in Jena, Germany, shows in a new study how leaf beetles could successfully use new and previously indigestible food sources in the course of evolution. The insects acquired enzymes from microorganisms via horizontal gene transfer that enabled them to degrade pectins, solid components of the plant cell wall. Since the degradation products resulting from pectin digestion are not per se crucial for the growth and development of the beetles, the researchers conclude that the beetles disrupt the cell wall to access the protein-rich cytoplasm of plant cells, which they need for their nutrition.

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More than microscopes can show

Computer simulations visualize how an essential stem cell protein opens wrapped DNA

A key protein for converting adult stem cells into cells that resemble embryonic stem cells has been visualized in unprecedented detail by an international team of researchers around Hans Schöler and Vlad Cojocaru of the Max Planck Institute for Molecular Biomedicine in Münster. By combing experiments and computer simulations, the team visualized how the Oct4 protein binds and opens short pieces of DNA while wrapped around nuclear storage proteins (histones), just like in our genome. The results were published in the journal Nucleic Acids Research on September 22.

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From Wound Healing to Regeneration

The phenomenon of regeneration was discovered over 200 years ago in the freshwater polyp Hydra. Until now, however, it was largely unclear how the orderly regeneration of lost tissues or organs is activated after injury. In its investigations of Hydra, an interdisciplinary research team at Heidelberg University was able to show how wound healing signals released upon injury are converted into specific signals of pattern formation and cell differentiation.

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Similarity of hepatocytes from liver and from stem cells improved

Research with stem cells is becoming increasingly important, because stem cells can develop into any body cell – skin cells, nerve cells or organ cells such as liver cells, the so-called hepatocytes. Stem cells can therefore be used, for example, in the therapy of organ damage or as an alternative to animal experiments. However, there are still major differences between hepatocytes obtained from a liver and those obtained from stem cells. Researchers at the Leibniz Research Centre for Working Environments and Human Factors in Dortmund (IfADo) have successfully identified an important reason for this difference, so that the two cell variants can be more similar in the future.

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Research grants endowed with €240,000 each

Scientists with a research focus on stem cell transplantation and cell therapy are invited to apply for the 2023 DKMS John Hansen Research Grant starting August 10, 2022. With this grant, the DKMS Stiftung Leben Spenden (Foundation for Giving Life) supports up to four outstanding research projects each year that aim to advance the medical progress and improve the chances of recovery for blood cancer patients. The requirements include a doctoral degree (PhD, MD or equivalent) that was obtained no longer than 10 years ago. The grants are endowed with €240,000 each, which will be paid out over a period of three years. The application deadline is December 2, 2022.

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Vitamin K prevents cell death: a new function for a long-known molecule

A team of researchers located at Helmholtz Munich reports on a novel function of vitamin K, which is generally known for its importance in blood clotting. The researchers discovered that the fully reduced form of vitamin K acts as an antioxidant efficiently inhibiting ferroptotic cell death. Ferroptosis is a natural form of cell death in which cellular iron plays an important role and which is characterized by the oxidative destruction of cellular membranes. In addition, the team identified FSP1 as the warfarin-insensitive enzyme reducing vitamin K, the identity of which had been postulated but remained unknown for more than half a century.

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How the genome is packed into chromosomes that can be faithfully moved during cell division

Researchers from the Gerlich Group at IMBA – Institute of Molecular Biotechnology of the Austrian Academy of Sciences – discovered a molecular mechanism that confers special physical properties to chromosomes in dividing human cells to enable their faithful transport to the progeny. The team showed how a chemical modification establishes a sharp surface boundary on chromosomes, thus allowing them to resist perforation by microtubules of the spindle apparatus. The findings are published in the journal Nature.

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Novel technology enables cell-protecting transfection of proteins and other macromolecules into living cells

„Top-fase“ is a simple and universal tool for the targeted transfection of numerous molecule species into cells and cell lines. This new method, developed at the BioQuant Centre of Heidelberg University, enables an accelerated and cost-efficient search for new biopharmaceuticals, the identification of intracellular drug targets, the optimisation of already existing drugs and the establishment of novel cellular assays.

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Covid-19: New energy for flagging immune cells

In severe Covid-19 patients, the metabolism produces insufficient amounts of certain energy-rich compounds called ketone bodies. However, these energy carriers are needed by two important cell types in the immune system in order to fight the virus effectively. Perhaps this finding explains why some people fall ill so much more severely than others. A study led by the University of Bonn at least points in this direction. The results have now been published in the journal Nature. They also give hope for new therapies.

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Competing cells: Cleaning up after yourself brings benefits

When different cell types compete in a confined space, those which remove debris faster have a better chance to dominate their environment. Researchers from the Max Planck Institute for Dynamics and Self-Organization (MPI-DS) showed in their model that not only a higher net proliferation rate, but also the swift removal of dead cells provides a competitive advantage. They mixed two cell populations only differing in debris removal rate and showed that already after a few generations the population with the higher removal rate starts to dominate the confined space.

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New Stem Cell Mechanism in Your Gut

Stem cells are a hot topic for creating medical treatments. However, scientists still do not fully understand how they choose to divide or differentiate to renew organs. Researchers have now found a new biophysical mechanism that regulates stem cells in the intestines of mice. There, a stem cell is not purely defined by intrinsic molecular markers but also by their location and movements in their environment. This could have implications for possible new treatments.

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Enzyme of bacterial origin promoted the evolution of longhorned beetles

Gene duplication increased the diversity and specificity of enzymes that enable larvae of longhorned beetles to degrade important wood components. Researchers at the Max Planck Institute for Chemical Ecology in Jena, Germany, looked closer at a group of digestive enzymes found only in this beetle family. They resurrected the primordial enzymes, which first appeared in a common ancestor of longhorned beetles. Horizontal gene transfer from bacteria to the beetle as well as ancient and recent gene duplications promoted the evolution of this family of digestive enzymes and enabled longhorned beetles to degrade the main components of the plant cell wall.

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Mass spectrometry-based draft of the mouse proteome

Proteins control and organize almost every aspect of life. The totality of all proteins in a living organism, a tissue or a cell is called the proteome. Using mass spectrometry, researchers at the Technical University of Munich (TUM) characterize the proteome, or protein complement of the genome, in important model organisms. In 2014, a team at the Chair of Proteomics and Bioanalytics reported a draft human proteome for the first time, followed by that of the model plant Arabidopsis thaliana in 2020, and now that of the most common laboratory mouse.

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Study at University Medicine Halle points to success of immunotherapy in the treatment of advanced stomach cancer

A clinical trial conducted by researchers at University Medicine Halle has shown that the lives of patients with a certain form of stomach cancer can be significantly prolonged when the current standard of care, which uses a combination of antibody therapy and chemotherapy to inhibit cell growth through receptor blockades, is supplemented by immunotherapy with the drug nivolumab.

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Building Block for a Longer Life

Proteins are existential building blocks of life that also have numerous functions in plants. An average plant cell contains more than 20 billion protein molecules that maintain cellular metabolism and stabilise their structure. Researchers at the Centre for Organismal Studies of Heidelberg University recently shed light on a cellular mechanism that extends the life of plant proteins. They have now identified a key protein that regulates this mechanism, which is known as N-terminal acetylation.

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How protists crack the walls of algae

The unicellular protist Orciraptor agilis produces a number of partly novel enzymes and binding proteins while penetrating the cell wall of dead microalgae. Such enzymes could potentially be useful in industrial applications / publication in ‘Current Biology’

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Precise blood diagnostics improve treatment outcome in non-small cell lung cancer patients

Non-small cell lung carcinoma is a particularly aggressive type of lung cancer. Tumor cells and tumor DNA (ctDNA) in the blood of patients with the disease can be analyzed by means of liquid biopsy throughout the course of the disease. This information is important in order to be able to target the constantly changing tumor. A study from the University of Bayreuth is the first to show that liquid biopsy significantly improves treatment outcomes in many cases and can be cost-effective in the German care system. The scientists present their research results in the Journal of Cancer Research and Clinical Oncology.

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MCM molecules impede the formation of DNA loops

The entire genomic material of a cell must be packed into a tiny cell nucleus in such a way, that on the one hand, it can be stored in an organized manner and, on the other hand, it can be transcribed, duplicated or repaired as needed. Different proteins are responsible for space-saving packaging, which can roll up or loop the DNA. Scientists Kikuë Tachibana and Karl Duderstadt from the Max Planck Institute of Biochemistry in Martinsried are investigating the exact task and function of these molecular machines. They discovered that the MCM complex plays an important role in restricting DNA loop formation and thus in the three-dimensional structure of the genome and in gene regulation.

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Process Chains for Isolation and Analysis: from Single Cells to Organoids

Researchers at the Fraunhofer Institute for Laser Technology ILT are working on new tools for the preparation and analysis of single cells and cell assemblies. The team developed the “Liftoscope”, a system for cell sorting for subsequent cultivation that can analyze and transfer biomaterials precisely and in a way that is gentle on cells. In addition to this system, further 3D bioprinting methods are increasingly finding their way into biotechnological research: Thanks to the development of microfluidic organ-on-a-chip systems, various cells can be arranged in a defined and reproducible manner to form artificial tissues.

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