Syndicate content

Archive

January 15th

Study on Recently Discovered Chlorophyll Molecule (Chl f) Could Be Key to Better Solar Cells; New Work Reveals Mechanism That Can Use Light on the Lower Energy Spectrum, Which Has Never Been Seen Before

All living organisms need energy for their survival, and this energy indirectly comes from the sun. Some organisms, such as plants, cyanobacteria, and algae, are capable of directly converting this light energy into chemical energy via a process called "photosynthesis.” These photosynthetic organisms contain special structures to mediate photosynthesis, called "photosystems.” There are two photosystems that carry out light-energy conversion reactions, each of which is composed of a number of proteins and pigments. Among photosynthetic pigments, chlorophyll is the most crucial one, which not only captures light energy from the sun, but also participates in the "electron transfer chain,” a molecular pathway through which photons (from the sunlight) are converted into electrons (which are used as an energy source). There are different types of chlorophyll molecules, each having a specific function ranging from absorbing light and converting it into energy. Moreover, each chlorophyll molecule absorbs light in different regions. Recently, a new type of chlorophyll called Chl f was discovered, but details such as exactly where it is located and how it functions have remained a mystery until now. In a new study published online on January 13, 2020 in Nature Communications, a team of researchers led by Professor Tatsuya Tomo, PhD, at the Tokyo University of Science, Japan, and including collaborating researchers from Okayama University, Tsukuba University, Kobe University, and RIKEN, revealed new details about the location and functions of Chl f.

January 14th

Researchers Develop High-Throughput Method to Study Effects of Removing Hundreds of “Poison Exons” at Same Time; With CRISPR-Based Method, Scientists Show That Poison Exons, Conserved for Over 80 Million Years, Are Essential & Have Anti-Tumor Activity

We don’t have much in common with mice. After 80 million years of diverging evolution, seeing any similarities in our DNA takes some squinting. So, it seems obvious that any bits of DNA that have resisted the forces of evolution and remained identical between mice and humans (and rats and pufferfish) must be critical--probably even essential. Known as “ultra-conserved elements,” these sections of DNA drew immediate scientific attention when the first human genome sequence was released in 2003. And while scientists have discovered some molecular functions for these elements, they have been failing to show their essentiality ever since--until now. In a new study published online on January 7, 2020 in Nature Genetics, scientists at the Fred Hutchinson Cancer Research Center in Seattle, Washington, showed that yes, these ultra-conserved DNA elements are indeed essential. The article is titled “RNA Isoform Screens Uncover the Essentiality and Tumor-Suppressor Activity of Ultraconserved Poison Exons.” Looking at a subclass of ultra-conserved elements known as “poison exons,” the investigators found that certain poison exons were essential for cell growth, while others acted to suppress the growth of lung tumor cells in mice. By showing that ultra-conserved elements operate on a cellular level, these discoveries help shed light on why they have remained unchanged over millions of years. This is the “first study finding large-scale importance of these highly conserved [DNA] elements,” said Dr. Rob Bradley (photo), PhD, a computational biologist and the study’s senior author. The 481 ultra-conserved DNA elements shared between mice, rats, and humans immediately jumped out once these three genomes were sequenced and compared. The finding was “really odd, really interesting,” Dr. Bradley said.

January 14th

Exosomes Promote Remarkable Recovery in Stroke

It’s been almost a quarter century since the first drug was approved for stroke. But what’s even more striking is that only a single drug remains approved today. In an open-access article published on December 6, 2019, in Translational Stroke Research, animal scientists, funded by the NIH, present brain-imaging data for a new stroke treatment that supported full recovery in swine, modeled with the same pattern of neurodegeneration as seen in humans with severe stroke. The open-access article is titled “Neural Stem Cell Extracellular Vesicles Disrupt Midline Shift Predictive Outcomes in Porcine Ischemic Stroke Model. “It was eye-opening and unexpected that you would see such a benefit after having had such a severe stroke,” said Steven Stice, PhD, Georgia Research Alliance Eminent Scholar and D.W. Brooks Distinguished Professor in the University of Georgia’s (UGA’s) College of Agricultural and Environmental Sciences. Dr. Stice is also Chief Science Officer for ArunA Biomedical Inc., and, prior to joining UGA, he was the co-founder of Advanced Cell Technology and served as both CSO and CEO of that company. “Perhaps the most formidable discovery was that one could recover and do so well after the exosome treatment.” Dr. Stice and his colleagues at UGA’s Regenerative Bioscience Center (RBC) report the first observational evidence during a midline shift—when the brain is being pushed to one side— to suggest that a minimally invasive and non-operative exosome treatment can now influence the repair and damage that follow a severe stroke. Exosomes are considered to be powerful mediators of long-distance cell-to-cell communication that can change the behavior of tumor and neighboring cells. The results of the study echo findings from other recent RBC studies using the same licensed exosome technology.

Bacteria As Artists; Surprising Beauty Found in Mixed Bacterial Cultures; Together, E. coli and A. baylyi Form Intricate Flower Patterns Under the Microscope; Non-Motile E. coli Hitching Ride on Motile A. baylyi Is Basis for "Artistic Beauty"

Microbial communities inhabit every ecosystem on Earth, from soil to rivers to the human gut. While monoclonal cultures often exist in labs, in the real world, many different microbial species inhabit the same space. Researchers at the University of California (UC) San Diego have discovered that when certain microbes pair up, stunning floral patterns emerge (see photo here and below). In a paper published online on January 14 in eLife, a team of researchers at UC San Diego's BioCircuits Institute (BCI) and Department of Physics, led by Research Scientist and BCI Associate Director Lev Tsimring, PhD, reports that when non-motile E. coli (Escherichia coli) are placed on an agar surface together with motile A. baylyi (Acinetobacter baylyi), the E. coli "catch a wave" at the front of the expanding A. baylyi colony. The agar provided food for the bacteria and also a surface on which E. coli couldn't easily move (making it non-motile). A. baylyi, on the other hand, can crawl readily across the agar using microscopic legs called pili. Thus, a droplet of pure E. coli would barely spread over a 24-hour period, while a droplet of pure A. baylyi would cover the entire area of the petri dish. Yet when the E. coli and A. baylyi were mixed together in the initial droplet, both strains flourished and spread across the whole area as the non-motile E. coli hitched a ride on the highly mobile A. baylyi. However, what most surprised researchers were intricate flower-like patterns that emerged in the growing colony over a 24-hour period.The open-access eLife article is titled “Flower-like patterns in multi-species bacterial colonies.

January 12th

First-Ever Integration of Metabolism, Expression, Thermodynamics, and ‘Omics Provides Algorithm That Is More Accurate and 10 to 100 Times Faster Than Previous State-of-the-Art Models of Metabolism

All living things are made of carbon, and sugars, e.g. glucose, are a very common source of it. Consequently, most cells are good at eating sugars, using enzymes to digest them through a series of chemical reactions that transform the initial sugar into a variety of cell components, including amino acids, DNA building blocks, and fats. Because they help these sugar-metabolism reactions run efficiently, the enzymes called biocatalysts. Given how critical all enzymes are to life itself, scientists have built several mathematical models that describe how the cells use enzymes to transform a sugar. Such models have been successfully used, for instance, to improve 2nd-generation biofuel production or identify drug targets for malaria, but they don't take into account the metabolic "cost" of producing the enzymes that catalyze all these chemical reactions. Accounting for this phenomenon, called "expression,” is key to describing many other phenomena, including beer fermentation and the growth of cancer cells. But all this first depends on accurately modeling the mechanisms of expression. Now, Professor Vassily Hatzimanikatis at EPFL (Ecole Polytechnique Fédérale de Lausanne)(photo)and Pierre Salvy, a PhD student in his lab, have developed a mathematical model that can efficiently model the expression of enzymes in living cells, as well as its associated metabolic cost. The model is called ETFL for "Expression and Thermodynamics Flux" and draws its accuracy from taking into account both biochemistry and thermodynamics (a set of physico-chemical laws that describe how energy flows in systems). Combining this with mathematical tools from the field of optimization, the researchers were able to drastically improve the accuracy of the model's predictions.

Sestrin Proteins May Provide Benefits of Exercise in Absence of Need to Work Out; Possible Small-Molecule Modulators of Sestrins Might Help Combat Muscle Wasting Due to Age or Disease

Whether it be a brisk walk around the park or high-intensity training at the gym, exercise does a body good. But what if you could harness the benefits of a good workout without ever moving a muscle? Researchers at Michigan Medicine at the University of Michigan and collaborators, studying a class of naturally occurring proteins called Sestrins have found that these proteins can mimic many of exercise's effects in flies and mice. The findings could eventually help scientists combat muscle wasting due to aging and other causes. The results of the researchers’ work were published online on January 13, 2020 in Nature Communications. The open-access article is titled “Sestrins Are Evolutionarily Conserved Mediators of Exercise Benefits.” "Researchers have previously observed that Sestrin accumulates in muscle following exercise," said Myungjin Kim, PhD, a Research Assistant Professor in the Department of Molecular & Integrative Physiology at Michigan Medicine. Working with Professor Jun Hee Lee, PhD, Dr. Kim and a team of collaborating researchers wanted to learn more about the protein's apparent link to exercise. Their first step was to encourage a group of flies to work out. Taking advantage of Drosophila flies' normal instinct to climb up and out of a test tube, collaborators Robert Wessells, PhD, and Alyson Sujkowski, both of Wayne State University in Detroit, developed a type of fly treadmill. Using it, the team trained the flies for three weeks and compared the running and flying abilities of normal flies with those of flies bred to lack the ability to make Sestrin. "Flies can usually run around four to six hours at this point and the normal flies' abilities improved over that period," says Dr. Lee. "The flies without Sestrin did not improve with exercise."

January 12th

Baby & Adult Brains “Sync Up” During Play, Princeton Study Shows; Findings Include Evidence That Babies’ Brains Actually Guide Adults During Certain Interactions

Have you ever played with a baby and felt a sense of connection, even though the baby couldn't yet talk to you? New research suggests that you might quite literally be "on the same wavelength," experiencing similar brain activity in the same brain regions. This is something that most mothers likely know instinctively, but it has now been proven scientifically and in great detail. A team of Princeton researchers has conducted the first study of how baby and adult brains interact during natural play, and they found measurable similarities in their neural activity. In other words, baby and adult brain activity rose and fell together as they shared toys and eye contact. The research was conducted at the Princeton Baby Lab (http://babylab.princeton.edu), where University researchers study how babies learn to see, talk, and understand the world. "Previous research has shown that adults' brains sync up when they watch movies and listen to stories, but little is known about how this 'neural synchrony' develops in the first years of life," said Elise Piazza, PhD, an Associate Research Scholar in the Princeton Neuroscience Institute (PNI) and the first author on a paper published online on December 17, 2019, in Psychological Science. The article is titled “"Infant and Adult Brains Are Coupled to the Dynamics of Natural Communication.” Dr. Piazza and her co-authors (Liat Hasenfratz, PhD, an Associate Research Scholar in PNI; Uri Hasson, PhD, a Professor of Psychology and Neuroscience and Director of Graduate Studies; and Casey Lew-Williams, PhD, an Associate Professor of Psychology) posited that neural synchrony has important implications for social development and language learning. Studying real-life, face-to-face communication between babies and adults is quite difficult.

New Work Suggests That Pancreatitis Is an FGF21-Deficient State That Can Be Corrected by FGF21 Replacement Therapy & Perhaps Also by a Second Treatment Strategy Employing a PERK Inhibitor

In work that could have clinical implications, University of Texas (UT) Southwestern (UTSW) researchers have found that humans and mice with pancreatitis are deficient in a stress hormone called fibroblast growth factor 21 (FGF21). Normally, FGF21 is more abundant in the pancreas than in any other organ in the body. The scientists also showed that replacement therapy reverses the condition in mouse models in about 24 hours and may even prevent it. The study also reports success with a second treatment strategy. A potential drug called a PERK inhibitor targets a different step in the integrated stress response, the cellular pathway affecting the amount of FGF21 available in the pancreas. “Given that several FGF21 drug candidates are, or soon will be, in clinical trials for conditions related to metabolic disease, it may be possible to test fibroblast growth factor 21 for treating human pancreatitis in the near future,” says David Mangelsdorf, PhD. In addition to being Chair of Pharmacology at UTSW, Dr. Mangelsdorf is an investigator in the Howard Hughes Medical Institute (HHMI). He adds that he knows of no current investigations of PERK inhibitors for clinical use. The new study was published online on January 8, 2020 in Science Translational Medicine and the open-access article is titled “Pancreatitis Is an FGF21-Deficient State That Is Corrected by Replacement Therapy.” Pancreatitis, a debilitating and sometimes deadly inflammation of the pancreas, can be acute or chronic. It accounts for about 275,000 U.S. hospitalizations each year, with its incidence on the rise for reasons that are unclear.

Functional Inhibition of Dopaminergic Neurons by Astrocyte GABA Identified As Core Cause of Parkinson's Disease; Findings Suggest New Form of Treatment for Patients in Early Stages of PD

As many as 7 to 10 million people in the world are thought to live with Parkinson's disease (PD). Being the second most common neurodegenerative disease, PD severely affects patients' quality of life, not just brining movement abnormalities. Despite its prevalence and negative impact, current medical treatments for PD rely on alleviating PD symptoms with little effort to explore ways to reverse the symptoms. It has been firmly believed that abnormal movements of PD begin in the brain where the production of dopamine, a neurotransmitter for movement control, is irreversibly impaired, i.e., in a state of neuronal death. Currently, L-DOPA, a potent PD medication is mainly prescribed to replenish dopamine in the deprived brain. However, such a treatment is symptomatic therapy, rather than a disease-modifying therapy. Long-term use of L-DOPA is well-known to cause serious side effects such as involuntary, erratic, and writhing movements. Led by Dr. C. Justin Lee, along with Dr. Hoon Ryu and Dr. Sang Ryong Jeon, researchers at the Center for Cognition and Sociality within the Institute for Basic Science (IBS), the Korea Institute of Science and Technology (KIST), and the Asan Medical Center (AMC) have discovered a new mechanism for PD pathology. The researchers reported that the symptoms of PD begin when dopaminergic neurons are "non-functional", even before they die off. Though the neuronal death had been till now believed to be the obvious cause of PD, the study found that the movement abnormalities of PD begin in the earlier stage when dopaminergic neurons, though being alive, cannot synthesize dopamine (they are in a “dormant” state). "Everyone has been so trapped in the conventional idea of the neuronal death as the single cause of PD.

January 11th

Specific Insulin-Like Peptide (ILP) Regulates How Beetle “Weapons” Grow; Study Reveals How Larval Nutrition Leads to Differently Sized Mandibles in Broad-Horned Flour Beetles

A scientist from Tokyo Metropolitan University and co-workers have discovered that a specific insulin-like peptide called insulin-like peptide 2 (ILP2) regulates the size of "weapons" in Gnatocerus cornutus beetles in different nutritional environments. They found diminished mandible size when expression of the peptide was suppressed, and that it was specifically expressed in the "fat body,” where beetles store nutrients. This has important implications for understanding how striking growth occurs in different environments for different organisms. The findings were published online on November 27, 2019 in PLOS Biology. The open-access article is titled “A Specific Type of Insulin-Like Peptide Regulates the Conditional Growth of a Beetle Weapon.” From deer antlers to beetle horns, the animal kingdom is full of examples of exaggerated ornaments and weapons which derive from sexual selection. Their growth and size may vary significantly from one specimen to another and give rise to distinct mating tactics like fighting, sneaking, or dispersing to areas with less competition. This variation is often correlated with body size or "condition" in a relationship known as positive allometry. Despite the importance of condition-dependent growth of these features, the mechanism behind how the environment affects the complex development of these observable features remains poorly understood. Insulin-like peptides (ILPs) and growth factors (IGFs) are found in a wide range of both invertebrates and vertebrates, like humans, and are thought to play common roles related to growth and metabolism. Recent work into the genetics of insects has revealed a wide variety of ILPs playing different functional roles. Examples include fruit flies which have 8 ILPs, pea aphids with 10 ILPs, and silkworms with over 40 ILPs.