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Archive - Feb 7, 2017

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Overcoming Hurdles in CRISPR Gene Editing to Improve Treatment

More and more scientists are using the powerful new gene-editing tool known as CRISPR/Cas9, a technology isolated from bacteria, that holds promise for new treatment of such genetic diseases as cystic fibrosis, muscular dystrophy, and hemophilia. But to work well, the new gene-clipping tool must be delivered safely across the cell membrane and into its nucleus, a difficult process that can trigger the cell's defenses and "trap" CRISPR/Cas9, greatly reducing its treatment potential. Now, researchers in nanochemistry expert Dr. Vincent Rotello's laboratory at the University of Massachusetts Amherst have designed a delivery system using nanoparticles to assist CRISPR/Cas9 across the membrane and into the cell nucleus while avoiding entrapment by cellular machinery. Details wrepublished online on January 27, 2017 in ACS Nano. The article is titled “Direct Cytosolic Delivery of CRISPR/Cas9-Ribonucleoprotein for Efficient Gene Editing.” The lab's experiment leader, Dr. Rubul Mout, says, "CRISPR has two components: a scissor-like protein called Cas9, and an RNA molecule called sgRNA that guides Cas9 to its target gene. Once the Cas9-sgRNA pair gets to the destination gene in the nucleus, it can interrogate its genetic mistakes and correct them with the help of the host cell's repair machinery." He points out that bcause CRISPR's potential was first discovered in 2012, gene editing or genome engineering has quickly become an intense research topic in biology and medicine. The goal is to treat otherwise incurable genetic diseases by manipulating diseased genes. "However, to achieve this, biotech and pharmaceutical companies are constantly searching for more efficient CRISPR delivery methods," he adds.

Adjusting Levels of Kynurenic Acid Can Have Significant Effects on Schizophrenic-Like Behavior in Mice

A new study by University of Maryland School of Medicine researchers, and collaborators, has found that in mice, adjusting levels of a compound called kynurenic acid (image) can have significant effects on schizophrenia-like behavior. The study was published online on December 16, 2016 in Biological Psychiatry. In recent years, scientists have identified kynurenic acid as a potential key player in schizophrenia. The article is titled “Adaptive and Behavioral Changes in Kynurenine 3-Monooxygenase Knockout Mice: Relevance to Psychotic Disorders.” People with schizophrenia have higher than normal levels of kynurenic acid in their brains. KYNA, as it is known, is a metabolite of the amino acid tryptophan; it decreases glutamate, and research has found that people with this illness tend to have less glutamate signaling than people without the disease. Scientists have theorized that this reduction in glutamate activity, and therefore the higher KYNA levels seen in patients, might be connected with a range of symptoms seen in schizophrenia, especially cognitive problems. For several years, Robert Schwarcz, Ph.D., a Professor in the Department of Psychiatry at the University of Maryland School of Medicine (UM SOM), who in 1988 was the first to identify the presence of KYNA in the brain, has studied the role of KYNA in schizophrenia and other neuropsychiatric diseases. For the new study, Dr. Schwarcz and his team collaborated closely with scientists at the Karolinska Institute in Stockholm, Sweden, the University of Leicester in the United Kingdom, and KynuRex, a biotech company in San Francisco. "This study provides crucial new support for our longstanding hypothesis," Dr. Schwarcz said. "It explains how the KYNA system may become dysfunctional in schizophrenia."

Over 40 Years of Research on Critically Endangered Nimba Toad Summarized in New Paper; Nimba Toad Is Known for Its Exceptional Reproductive Biology

The critically endangered Nimba toad has long been known for its exceptional reproductive biology. The females of this unique species give live birth to fully developed juveniles, having for nine months continuously provided nutrition to the fetuses in the womb (matrotrophy). While live birth (viviparity) among frogs and toads is rather an exception than a common characteristic, matrotrophy, in place of alternatives such as the fetus being fed with yolk, unfertilized eggs, or smaller siblings, is what makes the Nimba toad one of a kind. However, more than 40 years of research had not been comprehensively, accessibly, and completely summarized. The gap has recently been filled with a new paper, published on February 3, 2017 in the open-access journal Zoosystematics and Evolution by German scientists Drs. Laura Sandberger-Loua and Mark-Oliver Rödel, both affiliated with Museum für Naturkunde, Berlin, and Dr. Hendrik Müller, Friedrich-Schiller-Universität Jena. The article is titled “A Review of the Reproductive Biology of the Only Known Matrotrophic Viviparous Anuran, the West African Nimba Toad, Nimbaphrynoides occidentalis.” Studying the phenomenon, the scientists went through the literature published over four decades to gather the scattered details. They have also discussed the relationship between the toad's reproductive biology and its specific habitat of merely 4 km² of high altitude grasslands located at a minimum of 1,200 meters in the Nimba mountains, West Africa. The climate of the area is characterized by a rainy season lasting from April to October and a dry season from November to February/March. These seasons are found to determine the activity of the Nimba toads.