Biotechnology

Jan. 30, 2013 — A pair of University of Colorado Cancer Center studies published this month show that the milk thistle extract, silibinin, kills skin cells mutated by UVA radiation and protects against damage by UVB radiation -- thus protecting against UV-induced skin cancer and photo-aging. "When you have a cell affected by UV radiation, you either want to repair it or kill it so that it cannot go on to cause cancer. We show that silibinin does both," says Rajesh Agarwal, PhD, co-program leader of Cancer Prevention and Control at the CU Cancer Center and professor at the Skaggs School of Pharmacy and Pharmaceutical Sciences. The first study, published in the journal Photochemistry and Photobiology worked with human skin cells subjected to UVA radiation, which makes up about 95 percent of the sun's radiation that reaches Earth. The Agarwal Lab treated these UVA-affected cells with silibinin. With silibinin, the rate at which these damaged ...

Jan. 30, 2013 — Worldwide, many strains of the bacterium Staphyloccocus aureus are already resistant to all antibiotics except vancomycin. But as bacteria are becoming resistant to this once powerful antidote, S. aureus has moved one step closer to becoming an unstoppable killer. Now, researchers at the University of North Carolina at Chapel Hill have not only identified the mechanism by which vancomycin resistance spreads from one bacterium to the next, but also have suggested ways to potentially stop the transfer. The work, led by Matthew Redinbo, professor of chemistry at UNC's College of Arts and Sciences, addresses the looming threat of incurable staph infections -- a global public health problem that has mobilized scientists across disciplines to work together to identify the Achilles heel of these antibiotic-resistant bacteria. "We used to live in a world where antibiotics could readily cure bacterial disease," said Redinbo. "...

Jan. 29, 2013 — Many different tissues and organs form from pluripotent stem cells during embryonic development. To date it had been known that these processes are controlled by transcription factors for specific tissues. Scientists from the Max Planck Institute for Molecular Genetics in Berlin, in collaboration with colleagues at MIT and the Broad Institute in Boston, have now been able to demonstrate that RNA molecules, which do not act as templates for protein synthesis, participate in these processes as well. The scientists knocked down a gene for long non-coding RNA molecules (lncRNA) and thereby disrupted the development of the heart to an extent that was lethal to the embryos. Genesis of the ventral body wall was also impaired. It became apparent that the lncRNA participates in controlling transcription factors that themselves are responsible for controlling tissue- and organogenesis. The lncRNA itself thus acts as a modulating factor in these proc...

Jan. 29, 2013 — Hydrogen sulfide* (H 2 S) may play a wide-ranging role in staving off aging, according to a paper published online ahead of print in the journal Molecular and Cellular Biology . In this review article, a team from China explores the compound's plethora of potential anti-aging pathways. "H 2 S has been gaining increasing attention as an important endogenous signaling molecule because of its significant effects on the cardiovascular and nervous systems," the team writes. The evidence is mounting, they note, that hydrogen sulfide slows aging by inhibiting free-radical reactions, by activating SIRT1, an enzyme believed to be a regulator of lifespan, and probably through its interactions with a gene, klotho, which appears to have its own market basket of anti-aging activity. Hydrogen sulfide is produced within the human body, and has a variety of important physiological effects. For example, it relaxes the vascular endothelium a...

Jan. 28, 2013 — UCLA researchers, in a finding that runs counter to conventional wisdom, have discovered for the first time that a gene thought to express a protein in all cells that come under stress is instead expressed only in specific cell types. The group, from the Jules Stein Eye Institute and UCLA Pulmonary and Critical Care Medicine, focused on αB-Crystallin, a small heat shock protein. Heat shock proteins are a class of functionally-related proteins involved in the folding and unfolding of other proteins. Their expression is increased when cells are exposed to taxing environmental conditions, such as infection, inflammation, exercise, exposure to toxins and other stressors. αB-Crystallin may be associated with certain cancers and could be developed into a biomarker to monitor for diseases such as multiple sclerosis, age-related macular degeneration, heart muscle degeneration and clouding of the eye lens. Any discoveries about how this protein...

Jan. 28, 2013 — Sight would dramatically alter a blind man's understanding of an elephant, according to the old story. Now, a look directly at a cell surface is changing our understanding of cell membrane organization.  Using a completely new approach to imaging cell membranes, a study by researchers from the University of Illinois, Lawrence Livermore National Laboratory and the National Institutes of Health revealed some surprising relationships among molecules within cell membranes. Led by Mary Kraft, a U. of I. professor of chemical and biomolecular engineering, the team published its findings in the Proceedings of the National Academy of Sciences. Cells are enveloped in semi-permeable membranes that act as a barrier between the inside and outside of the cell. The membrane is mainly composed of a class of molecules called lipids, studded with proteins that help regulate how the cell responds to its environment. "Lipids have multiple fun...

Jan. 25, 2013 — Vanderbilt biochemists have discovered that the process bacteria undergo when they become drug resistant can act as a powerful tool for drug discovery. Their findings -- reported this week in the Online Early Edition of the Proceedings of the National Academy of Sciences -- should give a major boost to natural products drug discovery -- the process of finding new drugs from compounds isolated from living organisms -- by substantially increasing the number of novel compounds that scientists can extract from individual microorganisms. Bacteria have traditionally been the source of important drugs such as antibiotics and anticancer agents. Researchers looking for new bacterially synthesized drugs have long known that bacterial genomes contain a large number of "silent genes" that contain the instructions for making drug-like compounds. But, until now, scientists have found it is very difficult to find ways to turn on the producti...

Jan. 25, 2013 — Scientists at the Center for Translational Medicine at the Temple University School of Medicine are inching closer to solving a long-standing mystery in sepsis, a complex and often life-threatening condition that affects more than 400,000 people in the U.S. every year. By blocking the activity of a protein, STIM1, in cells that line the insides of blood vessels in mice, they have halted a cascade of cellular events that culminates in the out-of-control inflammation that marks sepsis, and protected lungs from severe damage. The findings, reported online January 25, 2013 in the Journal of Clinical Investigation , provide new insights into molecular details underlying sepsis and its effects on the lungs. In identifying STIM1 as a potential drug target, the results may lead to new treatment strategies against sepsis. "While antibiotics are improving, more than 25 percent of those who develop sepsis will die from it. This is partly becau...

Jan. 24, 2013 — In biology, molecules can have multi-way interactions within cells, and until recently, computational analysis of these links has been "incomplete," according to T. M. Murali, associate professor of computer science in the College of Engineering at Virginia Tech. His group authored an article on their new approach to address these shortcomings, titled "Reverse Engineering Molecular Hypergraphs," that received the Best Paper Award at the recent 2012 ACM Conference on Bioinformatics, Computational Biology and Biomedicine. Intricate networks of connections among molecules control the processes that occur within cells. The "analysis of these interaction networks has relied almost entirely on graphs for modeling the information. Since a link in a graph connects at most two molecules (e.g., genes or proteins), such edges cannot accurately represent interactions among multiple molecules. These interactions occur very of...

Jan. 24, 2013 — With projections of 9.5 billion people by 2050, humankind faces the challenge of feeding modern diets to additional mouths while using the same amounts of water, fertilizer and arable land as today. Cornell researchers have taken a leap toward meeting those needs by discovering a gene that could lead to new varieties of staple crops with 50 percent higher yields. The gene, called Scarecrow, is the first discovered to control a special leaf structure, known as Kranz anatomy, which leads to more efficient photosynthesis. Plants photosynthesize using one of two methods: C3, a less efficient, ancient method found in most plants, including wheat and rice; and C4, a more efficient adaptation employed by grasses, maize, sorghum and sugarcane that is better suited to drought, intense sunlight, heat and low nitrogen. "Researchers have been trying to find the underlying genetics of Kranz anatomy so we can engineer it into C3 crops," sa...

Jan. 23, 2013 — Researchers at Syracuse University's Department of Biomedical and Chemical Engineering at L.C. Smith College of Engineering and Computer Science are studying the toxicity of commonly used nanoparticles, particles up to one million times smaller than a millimeter that could potentially penetrate and damage cell membranes. In a recent article published along with cover art in the journal Langmuir, researchers Shikha Nangia, assistant professor of biomedical and chemical engineering (BMCE), and Radhakrishna Sureshkumar, Department Chair of BMCE and professor of physics, showed how simple shape and charge modifications of a nanoparticle can cause tremendous changes in the chemical interactions between the nanoparticle and a cell membrane. Nanomaterials, which are currently being used as drug carriers, also pose a legitimate concern, since no universal standards exist to educate and fully protect those who handle these materials. Nanopa...

Jan. 23, 2013 — A retrovirus called HERV-H, which inserted itself into the human genome millions of years ago, may play an important role in pluripotent stem cells, according to a new study published in the journal Retrovirology by scientists at UMass Medical School. Pluripotent stem cells are capable of generating all tissue types, including blood cells, brain cells and heart cells. The discovery, which may help explain how these cells maintain a state of pluripotency and are able to differentiate into many types of cells, could have profound implications for therapies that would use pluripotent stem cells to treat a range of human diseases. "What we've observed is that a group of endogenous retroviruses called HERV-H is extremely busy in human embryonic stem cells," said Jeremy Luban, MD, the David L. Freelander Memorial Professor in HIV/AIDS Research, professor of molecular medicine and lead author of the study. "In fact, HERV-H is ...

Jan. 22, 2013 — While working out the structure of a cell-killing protein produced by some strains of the bacterium Enterococcus faecalis , researchers stumbled on a bit of unusual biochemistry. They found that a single enzyme helps form distinctly different, three-dimensional ring structures in the protein, one of which had never been observed before. The new findings, reported in Nature Chemical Biology , should help scientists find new ways to target the enterococcal cytolysin protein, a "virulence factor that is associated with acute infection in humans," said University of Illinois chemistry and Institute for Genomic Biology professor Wilfred van der Donk, who conducted the study with graduate student Weixin Tang. Enterococcus faecalis (EN-ter-oh-cock-us faye-KAY-liss) is a normal microbial inhabitant of the gastrointestinal tracts of humans and other mammals and generally does not harm its host. Some virulent strains, however, produce c...

Jan. 22, 2013 — Stanford University School of Medicine investigators have found that for people harboring a genetic predisposition that is prevalent among Americans, beta carotene, which the body converts to a close cousin of vitamin A, may lower the risk for the most common form of diabetes, while gamma tocopherol, the major form of vitamin E in the American diet, may increase risk for the disease. The scientists used a "big data" approach to hunt down interactions between gene variants previously associated with increased risk for type-2 diabetes and blood levels of substances previously implicated in type-2 diabetes risk. In people carrying a double dose of one such predisposing gene variant, the researchers pinpointed a highly statistically significant inverse association of beta carotene blood levels with type-2 diabetes risk, along with a suspiciously high positive association of gamma tocopherol with risk for the disease. "Type-2 d...

Jan. 21, 2013 — A team of researchers based at Johns Hopkins has decoded a system that makes certain types of immune cells impervious to HIV infection. The system's two vital components are high levels of a molecule that becomes embedded in viral DNA like a code written in invisible ink, and an enzyme that, when it reads the code, switches from repairing the DNA to chopping it up into unusable pieces. The researchers, who report the find in the Jan. 21 early edition of the Proceedings of the National Academy of Sciences , say the discovery points toward a new approach to eradicating HIV from the body. "For decades, we've seen conflicting reports on whether each of these components helped protect cells from viruses," says James Stivers, Ph.D., a professor of pharmacology and molecular sciences at the Johns Hopkins University School of Medicine's Institute for Basic Biomedical Sciences. "By plotting how much of each are found in d...

Jan. 21, 2013 — Studies led by cell biologist Thomas Maresca at the University of Massachusetts Amherst are revealing new details about a molecular surveillance system that helps detect and correct errors in cell division that can lead to cell death or human diseases. Findings are reported in the current issue of the Journal of Cell Biology . The purpose of cell division is to evenly distribute the genome between two daughter cells. To achieve this, every chromosome must properly interact with a football-shaped structure called the spindle. However, interaction errors between the chromosomes and spindle during division are amazingly common, occurring in 86 to 90 percent of chromosomes, says Maresca, an expert in mitosis. "This is not quite so surprising when you realize that every single one of the 46 chromosomes has to get into perfect position every time a cell divides," he notes. The key to flawless cell division is to correct dangerous int...

Jan. 20, 2013 — Helper cells of the immune system can switch to become killer cells in the gut. The fate of mature T lymphocytes might be a lot more flexible than previously thought. New research from the RIKEN Center for Allergy and Immunology (RCAI) in Japan and La Jolla Institute for Allergy and Immunology (LIAI) in the USA shows for the first time that mature CD4+ helper T lymphocytes can be re-programed to become killer-like CD8+ T lymphocytes and gain killing functions. The findings are reported January 20 in the journal Nature Immunology , by a team of researchers led by Ichiro Taniuchi from RIKEN and Hilde Cheroutre from La Jolla. The team show using transgenic mice that mature CD4+ helper T lymphocytes that have lost the transcription factor ThPOK express genes specific to CD8+ killer T lymphocytes upon exposure to a specific environmental stimulation such as the gut. This turns them into killer cells that might act to control infection. CD4+ h...

Jan. 20, 2013 — Biotechnologists have been working hard to address the climate change and limited fossil resource issues through the development of sustainable processes for the production of chemicals, fuels and materials from renewable non-food biomass. One promising sustainable technology is the use of microbial cell factories for the efficient production of desired chemicals and materials. When microorganisms are isolated from nature, the performance in producing our desired product is rather poor. Metabolic engineering is performed to improve the metabolic and cellular characteristics to achieve enhanced production of desired product at high yield and productivity. Since the performance of microbial cell factory is very important in lowering the overall production cost of the bioprocess, many different strategies and tools have been developed for the metabolic engineering of microorganisms. One of the big challenges in metabolic engineering is to f...