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Archive - 2015

December 3rd

Targeted, Exosome-Mediated Delivery of Opioid Receptor siRNA for Treatment of Morphine Addiction; Results Suggest “Brand New Strategy to Treat Drug Relapse and Diseases of the Central Nervous System”

Scientists at the Jiangsu Engineering Research Center for MicroRNA Biology and Biotechnology at Nanjing University in China have shown that exosomes modified to express the neuron-specific rabies viral glycoprotein (RVG) peptide on their membrane surface can be used to deliver opioid receptor mu (MOR) siRNA into the brain to treat morphine addiction. In an open-access article published online today (December 3, 2015) in Scientific Reports, the researchers described results demonstrating that MOR siRNA could be efficiently packaged into RVG exosomes and was associated with argonaute 2 (AGO2) in these exosomes. The modified exosomes efficiently and specifically delivered MOR siRNA into Neuro2A cells and the mouse brain, the scientists said. Functionally, the siRNA-loaded RVG exosomes significantly reduced MOR mRNA and protein levels. MOR siRNA delivered by the RVG exosomes strongly inhibited morphine relapse via the down-regulation of MOR expression levels. The new article is titled “Targeted Exosome-Mediated Delivery of Opioid Receptor Mu siRNA for the Treatment of Morphine Relapse.” As background, the researchers said that MOR is a major target of opioid drugs and appears to play critical roles in mediating the major effects of these drugs, including analgesia, tolerance, abuse, dependence, and respiratory depression. It has been reported, the authors said, that the rewarding effect of morphine, mediated by MOR, is abolished in MOR-deficient mice and that a MOR antagonist diminished the consequences of an initial opioid drug relapse. Therefore, the researchers selected the MOR as a target for the treatment of drug addiction.

First Report of Hibernating Primate Existing Outside Madagascar; Pygmy Loris in Southeast Asia Newly Shown to Hibernate; Possibly Major Clue to Better Understanding of Evolution of Hibernation

Up until now, three species of lemurs on Madagascar were the only primates known to hibernate. Researchers at Vetmeduni Vienna in Austria, have now reported, for the first time, that another primate species, the pygmy slow loris that lives in Vietnam, Cambodia, Laos, and China, the pygmy slow loris, also uses hibernation to save energy. The results were published online today (December 3, 2015) in an open-access article in Scientific Reports. The article is titled “Hibernation in the Pygmy Slow Loris (Nycticebus Pygmaeus): Multiday Torpor In Primates Is Not Restricted to Madagascar.” Hibernation is a state of energy conservation during which body temperature and metabolism are drastically reduced. If this state lasts longer than 24 hours, it is called hibernation. Shorter periods are called daily torpor. There are many mammals that hibernate. However, among primates hibernation is a rare capability, as it had been previously found in only three species of lemurs. Lemurs live exclusively on the island of Madagascar off the east coast of Africa, where they hibernate during the dry season, mainly to conserve water. Now a team at the Research Institute of Wildlife Ecology at the Vetmeduni Vienna, collaborating with colleagues from the Vietnamese Endangered Primate Rescue Center, has discovered another primate that hibernates: the pygmy slow loris (Nycticebus pygmaeus). These animals belong to the group of so-called “wet nosed primates.” They reach a body length of 7.7 inches to 9.1 inches and a body mass (adult males) of approximately 15 ounces. They live in Southeast Asia and are nocturnal, tree-living (arboreal) animals. The researchers investigated the body temperatures of five pygmy lorises in fall, winter, and spring in a Vietnam primate reservation.

December 2nd

Failure of Efforts to Block miR-17 in Triple-Negative Breast Cancer Explained; Guide & Passenger Strands of miR-17 Both Active in Suppressing Tumor Suppressor Genes PDCD4 and PTEN; New Efforts Will Target miR-17 Without Imitating Passenger Strand

Researchers at Thomas Jefferson University in Philadelphia, Pennsylvania have discovered why conventional efforts to block a tiny strand of ribonucleic acid, called microRNA, in triple-negative breast cancer cells failed. In a study published online today (December 2, 2015) in the open-access journal PLOS ONE, the new insight may enable effective design of RNA blockers against previously intractable microRNAs. The new report is titled “Non-Specific Blocking of Mir-17-5p Guide Strand in Triple Negative Breast Cancer Cells by Amplifying Passenger Strand Activity.” “Triple-negative breast cancer is one of the most aggressive forms of breast cancer, and there's been a lot of excitement in blocking the microRNAs that appear to make this type of cancer grow faster and resist conventional treatment," says senior author Eric Wickstrom, Ph.D., a Professor in the Department of Biochemistry and Molecular Biology at the Sidney Kimmel Medical College (SKMC) at Thomas Jefferson University. "However blocking microRNAs hasn't met with great success and this paper offers one explanation for why that might be the case." "Triple-negative breast cancer strikes younger women, tragically killing them in as little as two years," says first author Yuan-Yuan Jin, a Ph.D. candidate in the SKMC Department of Biochemistry and Molecular Biology. "Only chemotherapy and radiation are approved therapies for triple-negative breast cancer. We want to treat a genetic target that will keep patients alive with a good quality of life." The researchers targeted a microRNA called miR-17 that is known to spur triple-negative breast cancer growth by interfering with genes that would normally signal a diseased or early-cancerous cell to die. Specifically, miR-17 blocks the tumor suppressor genes PDCD4 and PTEN. However, when Ms.

Trap-Jaw Ants in Borneo Exhibit Jumping Behavior Never Seen Before in the Species; Behavior Allows Targeted Jumping in Addition to Haphazard Defense & Escape Jumping Previously Observed

A species of trap-jaw ant has been found to exhibit a previously unseen jumping behavior, using its legs rather than its powerful jaws. The discovery makes this species,Odontomachus rixosus, the only species of ant that can jump with either its legs or its mandibles. This new finding was reported online on December 1, 2015 in Frontiers in Ecology and the Environment. The article is titled "Snap! Trap-Jaw Ants in Borneo Also Jump Using Their Legs." "Jumping behavior in ants is incredibly rare," says Magdalena Sorger, a recent Ph.D. graduate of North Carolina State University and sole author of the paper reporting the discovery. "Out of 326 genera of ants, only three genera jump using their legs. Another three genera are known to jump using their jaws. But now we know that one species of jaw-jumping ant uses its legs as well. That's extremely interesting." It's long been known that all Odontomachus species are capable of hurling themselves through the air using their jaws, and they can do this in two ways. They can "escape jump" to flee a threat by snapping their jaws against the ground, which throws them into the air. When they do this, they often land on their backs and appear to have little control over where they land. They can also do a "bouncer defense jump," using their jaws against whatever's in front of them to propel themselves backwards. But, as with the escape jump, they often land haphazardly. But, while doing fieldwork in Borneo, Dr. Sorger observed a type of jumping behavior in O. rixosus that had never been previously reported in any Odontomachus species. The new behavior, which Dr. Sorger calls a leg-jump, appears to be used primarily, if not exclusively, as an escape mechanism.

December 1st

Vastly Different Neural Circuitry Underlies Problems That Seem Similar on Surface in Different Patients With Schizophrenia; Almost Complete Lack of Circuit Overlap Can Exist Between Different Sub-Symptoms

Schizophrenia, a severe mental disorder affecting approximately 1 in 100 people around the world, is notoriously difficult to diagnose and treat, in large part because it manifests differently in different people. The results of a new study, first published online on October 17, 2015 in an open-access article in Molecular Neuropsychiatry, may help explain why. The article is titled “Neural Correlates of Schizophrenia Negative Symptoms: Distinct Subtypes Impact Dissociable Brain Circuits.” Researchers at the University of North Carolina School of Medicine, together with colleagues at multiple major institutions, have created a map that shows how specific schizophrenia symptoms are linked to distinct brain circuits. The findings add to a growing body of evidence that schizophrenia is not a single disease but a complex constellation of neural circuit problems. The study also reinforces the potential value of brain scans for identifying and understanding schizophrenia in individual patients, for finding promising new therapeutic approaches, and for helping clinicians track a patient's progress during therapy. "For a long time, we've thought of brain imaging studies as mainly a way to corroborate or confirm aspects of brain function and pathology that we had already identified from studying a patient's behavior," said Aysenil Belger, Ph.D., Professor of Psychiatry and Psychology at UNC and the study's senior author. "This approach, where we use brain imaging to dissect the specific neural pathways of complex syndromes, is very novel and important. The imaging can help us distinguish between the different brain networks that contribute to distinct sub-symptoms. These distinctions are not recognizable from behavioral observations alone." Dr.

Sponges (Porifera) Constitute Oldest Extant Animal Phylum, New Study Reports; Findings Support Classical View of Early Animal Evolution

Who came first – sponges or comb jellies? A new study by an team of researchers at Ludwig-Maximilians-Universitaet (LMU) in Munich, Germany reaffirms that sponges are the oldest animal phylum – and restores the classical view of early animal evolution, which recent molecular analyses had challenged. The answer to the question of whether the sponges or the comb jellies (also known as sea gooseberries) represent the oldest extant animal phylum is of crucial importance to our understanding of organismic evolution. The two possible solutions have very different consequences for our understanding of central aspects of the early evolution of multicellular animals (Metazoa), such as the origins of nervous systems, tissues, and organs. In recent years, new data have once again brought this issue into focus and given rise to controversial debates among zoologists. Now, a re-analysis of the evidence by an international group of evolutionary biologists has convincingly refuted the proposition that comb jellies are the phylogenetically oldest extant metazoan group. The new study, a collaborative effort by groups led by Professor Gert Wörheide (Chair of Paleontology and Geobiology at LMU) and Dr. Davide Pisani (Bristol University, UK) reaffirms the traditional view that the sponges were the first phylum to diverge from the common ancestor of metazoans. “Some recent studies seemed to imply that comb jellies were the trendsetters in animal evolution. But we were able to disprove this idea by using more powerful and sophisticated methods to analyze the genetic data presented in those studies,” says Dr. Wörheide. The new results were published online on November 30, 2015 in PNAS.

Testosterone Treatment "Dramatically" Increases Insulin Sensitivity in Men with Type 2 Diabetes Who Also Have Low Testosterone Levels; 32% Increase in Glucose Uptake by Tissues Seen in Response to Insulin in Treated Men

Men with type 2 diabetes who have low testosterone levels can benefit significantly from testosterone treatment. That is the conclusion of University at Buffalo (UB) researchers who conducted the first randomized, double-blind, placebo-controlled study of testosterone treatment in type 2 diabetic men that comprehensively investigated the role of insulin resistance and inflammation, before and after treatment with testosterone. The study, funded by the NIH, was published online on November 29, 2015 in Diabetes Care. The article is titled “Insulin Resistance and Inflammation in Hypogonadotropic Hypogonadism and Their Reduction After Testosterone Replacement in Men With Type 2 Diabetes.” "This is the first definitive evidence that testosterone is an insulin sensitizer and hence a metabolic hormone," said Paresh Dandona, M.D,. Ph.D., senior author on the paper and State University of New York (SUNY) Distinguished Professor and Chief of Endocrinology, Diabetes, and Metabolism in the Department of Medicine in the Jacobs School of Medicine and Biomedical Sciences at UB. He sees patients at UBMD Internal Medicine. The UB researchers found that low testosterone levels were associated with significantly decreased insulin sensitivity; this was demonstrated by a 36 percent decrease in the rate at which glucose is taken up by tissues when patients with low testosterone were administered a set concentration of insulin. Dr. Dandona and his co-authors have been reporting on the relationship between insulin sensitivity and testosterone in type 2 diabetic males since the publication of their seminal paper in 2004, when they demonstrated the association between low testosterone levels and type 2 diabetes. This association was extended to obesity in 2010 in a study of more than 2,000 obese men.

Coordinated Shared Parenting Shown to Be Beneficial for Baby Birds

Long-tailed tits are more successful at raising young chicks when they alternate their feeding trips, scientists from the the UK’s University of Sheffield have found. A new study shows that parents who take it in turns to feed their chicks in the nest give their young more food and better protect them from being eaten by predators, in comparison to those who give them food at random intervals. This is the first time the strategy, which is similar to humans sharing late-night feeds, has been shown to benefit the family group. Lead author of the research, Kat Bebbington, Ph.D., said: “Parents with a young baby often take it in turns to do the grueling night-time feeds so that neither of them gets too exhausted. This is a situation we are all familiar with as humans, but there’s almost no evidence for animals doing this in nature. Our research shows that, for long-tailed tits at least, coordinating and alternating parental responsibilities like feeding can mean the difference between life and death for chicks.” The new research, which was published online on November 30, 2015 in the journal Behavioral Ecology, suggests that parents who take turns visiting the nest do so by making sure they both arrive at the nest at the same time. The article is titled “Coordinated Parental Provisioning Is Related to Feeding Rate and Reproductive Success in a Songbird.” This strategy allows the parents to keep an eye on whose turn it is to feed, but also means that, over the course of the day, parents spend less time near the nest than they would do if each visited the nest alone. Scientists believe this is the reason why chicks are less likely to be eaten if their parents take turns to feed them – visually-based predators like foxes and crows are less likely to be attracted to the nest if the parents are not flying around it as often.

First Language Wires Brain for Later Language-Learning; Results Point to Unique and Lasting Influence of Early Language Experience on Later Brain Organization

You may believe that you have forgotten the Chinese you spoke as a child, but your brain hasn’t. Moreover, that “forgotten” first language may well influence what goes on in your brain when you speak English or French today. In an open-access article published online today (December 1, 2015) in Nature Communications, researchers from McGill University and the Montreal Neurological Institute in Canada describe their discovery that even brief, early exposure to a language influences how the brain processes sounds from a second language later in life--even when the first language learned is no longer spoken. It is an important finding because this research tells scientists both about how the brain becomes wired for language, and also about how that hardwiring can change and adapt over time in response to new language environments. The research has implications for our understanding of how brain plasticity functions, and may also be important information about creating educational practices geared to different types of learners. The article is titled “Past Experience Shapes Ongoing Neural Patterns for Language.” In the new study, researchers asked three groups of children (aged 10 - 17) with very different linguistic backgrounds to perform a task that involved identifying French pseudo-words (such as vapagne and chansette). One group consisted of children born and raised in unilingual French-speaking families. The second group consisted of children adopted from China into a French-speaking family before age three, who stopped speaking Chinese at that time, and from that point on heard and used only French. The third group consisted of children fluently bilingual in Chinese and French.

New Diaphragm Tissue Grown from Stem Cells & 3D Scaffolds Offers Hope of Cure for Common Birth Defect and Possibly Future Repairs of Heart Muscle; Possibilities Are “Enormous” Karolinska Tissue Regeneration Expert Says

An international collaboration among scientists in Sweden, Russia, and the United States has resulted in the successful engineering of new diaphragm tissue in rats using a mixture of stem cells and a 3D scaffold. When transplanted, this tissue has regrown with the same complex mechanical properties of diaphragm muscle. The study was published online on November 14, 2015 in the journal Biomaterials, and offers hope of a cure for a common birth defect and also for possible heart muscle repairs in the future. The article is titled “Orthotopic Transplantation of a Tissue Engineered Diaphragm in Rats.” The multi-disciplinary team behind the current study includes world-renowned researchers in the field of regenerative medicine and tissue engineering: Paolo Macchiarini, M.D., Ph.D., Director of the Advanced Center for Regenerative Medicine and Senior Scientist at the Karolinska Institute in Sweden; Doris Taylor, Ph.D., Director of Regenerative Medicine Research at the Texas Heart Institute in the USA; and Mark Holterman, M.D., Ph.D., Professor of Surgery and Pediatrics at the University of Illinois College of Medicine in Peoria, Illinois, USA; working in collaboration with a research team at the Kuban State Medical University in Russia. The diaphragm is a sheet of muscle that has to contract and relax constantly to allow breathing. It is also important in swallowing, and acts as a barrier between the chest cavity and the abdomen. Malformations or holes in the diaphragm are found in 1 in 2,500 babies and can cause extreme, often fatal, symptoms. At the moment, surgical repair of large defects like these involves using an artificial patch, which will not grow with the infant and does not provide any contraction to assist with breathing.