Posts Tagged: biology

Space-like gravity weakens muscle development

Space-like gravity weakens muscle development

Microgravity conditions affect DNA methylation of muscle cells, slowing their differentiation   Astronauts go through many physiological changes during their time in spaceflight, including lower muscle mass and slower muscle development. Similar symptoms can occur in the muscles of people on Earth’s surface, too. In fact, it could affect everyone to some extent later in life. “Age-related skeletal muscle disorders, such as sarcopenia, are becoming a greater concern in society,” said Hiroshima University (HU) Professor and Space Bio-Laboratories Director Louis Yuge. “It is especially a big concern in Japan, where the number of aging people is increasing.” In a study published in Microgravity, a medical research group at HU led by Yuge shed light… Read more

Transcription factor helps tumors grow in low oxygen, resist anticancer therapies

Transcription factor helps tumors grow in low oxygen, resist anticancer therapies

  An international team of researchers found how cancer cells respond to DNA damage signaling when in low oxygen, or hypoxia. Through comprehensive gene expression analyses, the team determined how one family of genes controls DNA damage response, as well as how it weakens the effectiveness of anticancer therapies. Our bodies have strict molecular mechanisms that help us respond to hypoxia. These mechanisms are not just limited to helping us adapt to higher altitudes when climbing up a mountain. They also arise in diseases such as anemia, diabetes, or cancers. In the case of a new study led by Keiji Tanimoto’s team at Hiroshima University (HU), hypoxia indicates developments or… Read more

Highly safe biocontainment strategy hopes to encourage greater use of GMOs

Highly safe biocontainment strategy hopes to encourage greater use of GMOs

Hiroshima University researchers believe their simple phosphite-based control method will convince legislators to get with the times Use of genetically modified organisms (GMOs) – microorganisms not found in the natural world but developed in labs for their beneficial characteristics – is a contentious issue. For while GMOs could greatly improve society in numerous ways – e.g. attacking diseased cells, digesting pollution, or increasing food production – their use is heavily restricted by decades-old legislation, for fear of what might happen should they escape into the environment. For researchers, aware of their potential, it is important to develop safety strategies to convince legislators they are safe for release. For this reason… Read more

“Smart” genetic library – making disease diagnosis much easier

“Smart” genetic library – making disease diagnosis much easier

Hiroshima University finds way to determine disease-causing mutations Researchers at Hiroshima University have developed a smart genetic reference library for locating and weeding out disease-causing mutations in populations. The technique and database, developed by Dr. Satoshi Okada, of HU’s Graduate School of Biomedical & Health Sciences, has successfully estimated naturally occurring rare-variants in the STAT1 gene – and determined the diseases that would result. Using alanine scanning – a method for assessing the functional potential of genes, this study, the first of its kind, should assist doctors in diagnosing primary-immunodeficiency in patients.   STAT1 The STAT1 gene plays an important function in host immunity, through its role as a mediator… Read more

Kazunori Imaizumi, biochemistry

Kazunori Imaizumi, biochemistry

A Conversation with Distinguished Professor Kazunori Imaizumi A Common Cause Inside the cells of animals and plants is a folded, flattened tube of membranes piled on top of themselves. Studded along portions of the inside of this tube are ribosomes, small organelles that turn messages from DNA into protein. The proteins and occasionally important fats, or lipids, travel through the tube, folded and finalized into their completed form as they go. The tube itself is the Endoplasmic Reticulum, referred to as “the ER” by scientists. If something goes awry within the ER, proteins and lipids can get backed-up, clogging the tube and causing cellular stress. Both the potential causes and… Read more

How females store sperm: fertility study in chickens examines fatty acids

How females store sperm: fertility study in chickens examines fatty acids

The science of breeding chickens has revealed part of the mystery of how certain female animals are able to store sperm long-term.  Droplets of fat transferred from female cells to sperm cells may contribute to keeping sperm alive. Females of some types of insects, reptiles, and birds can store sperm from multiple males within specialized sperm storage areas of their reproductive tracts.  Different animals can store sperm for days or years.  Stored sperm can fertilize multiple eggs over time, meaning females do not need to mate again to fertilize additional eggs. “Farmers may be able to more successfully breed their flocks if we could understand how the sperm stays viable… Read more

Active deformations of cell nuclei contribute to intra-nuclear architecture formations

Active deformations of cell nuclei contribute to intra-nuclear architecture formations

There are two types of chromatin, euchromatin and heterochromatin, that vary with the stages of the cell cycle. In particular, euchromatin with rich active genes localizes to the interior of the nucleus during interphase; heterochromatin usually localizes to the periphery of the nucleus. Akinori Awazu, an Associate Professor at the Research Center for Mathematics on Chromatin Live Dynamics (RcMcD) has investigated the contributions of active deformation dynamics of cell nuclei to the intra-nuclear positioning of euchromatin and heterochromatin using the Brownian motion theory. Professor Awazu analyzed the behaviors of model chains containing two types of regions (representing euchromatin and heterochromatin); one with high and the other with low mobility. These… Read more

A genetic polymorphism associated with lung cancer progression

A genetic polymorphism associated with lung cancer progression

Genetic polymorphisms associated with cancer progression lead to variations in gene expression and may serve as prognostic markers for lung cancer. Researchers at the Hiroshima University and Saitama Medical University found that in patients with lung cancer, a single nucleotide polymorphism (SNP) may regulate gene and protein expression and be associated with poor prognosis. To establish this genetic polymorphism as a useful clinical prognostic marker and to further clarify its molecular mechanism, large-scale clinicopathological studies of lung cancer and/or other types of cancer are required for additional insights. Hypoxia-inducible factor-2 alpha (HIF-2 alpha or EPAS1) is important for cancer progression, and its overexpression is considered a putative biomarker for poor… Read more

A study of antidepressants reveals how treatment helps depression management

A study of antidepressants reveals how treatment helps depression management

  Researchers in Japan have shown that several different classes of antidepressants increase early growth responses in astrocytes, star-shaped glial cells, which could help develop new treatments. Amitriptyline is a prototypical antidepressant that is currently used worldwide. Generally, effects of antidepressants such as amitriptyline in depressive patients become evident after treatment for a few weeks. However, no study has investigated the reasons why effects are not immediately evident. Previous studies have shown that amitriptyline increases the mRNA expression of fibroblast growth factor 2 (FGF2) in rat astrocytes, not neurons, slowly over 24 hours. However, the cellular mechanism that leads to the expression of FGF2 following amitriptyline treatment remains unclear. In… Read more

Potential of disk-shaped small structures, coccoliths

Potential of disk-shaped small structures, coccoliths

To promote efficient bioenergy production Researchers at Hiroshima University and the University of Tsukuba showed that coccolith disks made of calcium carbonate in Emiliania huxleyi, one of the promising biomass resources, potentially perform roles in reducing and enhancing the light that enters the cell by light scattering. Elucidation of the physiological significance of coccolith formation in E. huxleyi can help promote efficient bioenergy production using microalgae. The energy issue is one of the most important problems on earth. Recently, many types of renewable energy resources such as solar light, wind, water, and biomass have attracted attention for their use as alternatives for fossil fuels. Coccoliths are disk-shaped plates of calcium carbonate formed by… Read more