Syndicate content

Archive - Jul 24, 2015

Scientists ID Protein of Rice Bacterial Blight Pathogen That Activiates XA21 Immune Receptor in Rice; Discovery Has Implications for Worldwide Rice Supply, Future Grass-Type Biofuel Crops, and Perhaps Even Human Disease

A bacterial signal that, when recognized by rice plants, enables the plants to resist a devastating blight disease has been identified by a multi-national team of researchers led by scientists with the U.S. Department of Energy (DOE)'s Joint BioEnergy Institute (JBEI) and the University of California (UC) Davis. The research team discovered that a tyrosine-sulfated bacterial protein called "RaxX," activates the rice immune receptor protein called "XA21." This activation triggers an immune response against Xanthomonas oryzaepv.oryzae (Xoo), a pathogen that causes bacterial blight, a serious disease of rice crops. "Our results show that RaxX, a small, previously undescribed bacterial protein, is required for activation of XA21-mediated immunity to Xoo," says Dr. Pamela Ronald, a plant geneticist for both JBEI and UC Davis, who led this study. "XA21 can detect RaxX and quickly mobilize its defenses to mount a potent immune response against Xoo. Rice plants that do not carry the XA21 immune receptor or other related immune receptors are virtually defenseless against bacterial blight." Dr. Ronald, who directs JBEI's grass genetics program and is a professor in the UC Davis Department of Plant Pathology, is one of two corresponding authors of an open-access paper describing this research that was published in the July 3, 2015 issue of Science Advances. The other corresponding author was Dr. Benjamin Schwessinger, a grass geneticist with JBEI's Feedstocks Division at the time of this study, and now with the Australian National University. The Science Advances paper is titled "The Rice Immune Receptor XA21 Recognizes a Tyrosine-Sulfated Protein from a Gram-Negative Bacterium."

Initiation of Phase 1/2a Clinical Trial of Antisense Drug for Huntington’s Disease Announced by ISIS Pharmaceuticals; ISIS Earns $22 Million Milestone Payment from Collaborator Roche

On July 21, 2015, Isis Pharmaceuticals, Inc. (NASDAQ: ISIS) today announced that it has initiated a Phase 1/2a clinical trial of ISIS-HTTRx in patients with Huntington's disease (HD). ISIS-HTTRx is the first therapy to enter clinical development that is designed to directly target the cause of the disease by reducing the production of the protein responsible for HD. HD is a rare genetic neurological disease in which patients experience deterioration of both mental abilities and physical control. Presently, there are no disease-modifying treatments for HD, with current therapies focused only on treating disease symptoms. ISIS-HTTRx has been granted orphan drug designation by the European Medicines Agency for the treatment of patients with HD. Orphan drug designation is granted to products designed to diagnose, prevent, or treat life-threatening or very serious conditions that affect not more than five in 10,000 persons in the European Union. "Although the toxic protein produced from the huntingtin (HTT) gene in HD patients has been a target of interest for many years, no therapies have advanced to clinical trials to treat the underlying cause of the disease. Our antisense technology has enabled us to discover and develop ISIS-HTTRx, the first therapeutic approach designed to treat the genetic cause of HD. Together with Roche, we are committed to investigating this approach to treat patients with HD, a devastating disease that typically affects generations of families," said C. Frank Bennett, Ph.D., Senior Vice President of Research at Isis Pharmaceuticals. "Initiating the clinical study of ISIS-HTTRx in patients with HD is the first step in developing a treatment that could significantly impact a patient's disease. It is also an important milestone in our collaboration with Roche.

Glaucoma Medication May Be Effective in Treatment of Tuberculosis, Even Drug-Resistant Forms; Effectiveness Revealed in Screening of 273,000 Compounds

A new discovery by Michigan State University (MSU) scientists suggests that a common medication used to treat glaucoma could also be used to treat tuberculosis (TB), even the drug-resistant forms. Dr. Robert Abramovitch, an MSU microbiologist, along with graduate student Benjamin Johnson, who helped lead the study, have discovered that ethoxzolamide, a sulfa-based compound found in many prescription glaucoma drugs, actually turns off the TB mycobacterium's ability to invade the immune system. The research paper was published in the August 2015 issue of Antimicrobial Agents and Chemotherapy. The article is titled “The Carbonic Anhydrase Inhibitor Ethoxzolamide Inhibits the Mycobacterium tuberculosis PhoPR Regulon and Esx-1 Secretion and Attenuates Virulence.” "Basically, ethoxzolamide stops TB from deploying its weapons...shutting down its ability to grow inside certain white blood cells in the immune system," Dr. Abramovitch said. "We found the compound reduces disease symptoms in mice." According to Dr. Abramovitch, TB mycobacteria may not have eyes and ears, but they have an uncanny ability to sense certain environmental cues in the body and to adapt. One of these abilities is the organism’s ability to detect pH, which is key because particular acid levels indicate to the organism that it is being attacked by a host immune cell and prompt the organism to take effective counter-measures. "The compound we found inhibits TB's ability to detect acidic environments, effectively blindfolding the mycobacterium so it can't resist the immune system's assault," Dr. Abramovitch said. It's estimated that 2 billion people, globally, carry the TB infection, but in most cases it lies dormant and the immune system is able to prevent it from spreading through the body. "It's a standoff, however," Dr.

Mitochondrial DNA Sequencing of Butteflies on Iberian Peninsula Reveals High Level of Potentially New Species; DNA Barcode Reference Library Established; Libray Should Aid Critical Conservation Efforts

Since 2006, a team of researchers has sequenced the mitochondrial DNA of all the known species of butterflies on the Iberian peninsula (228) and its main populations. The result is a report that compiles more than 3500 genetic sequences of all the species, which have been compared to the genetic sequences of other European buttefly populations. The open-access article was published online on July 24, 2015 in Scientific Reports. It is titled “DNA Barcode Reference Library for Iberian Butterflies Enables a Continental-Scale Preview of Potential Cryptic Diversity.” The paper has 277 pages of supplementary material, including pictures and 80 maps of the geographical distribution of the butterfly genetic lineages identified. This is the first time that the butterfly community of two entire countries (Spain and Portugal) has been thoroughly analyzed. Surprisingly, the mtDNA sequences obtained suggest that up to the 28% of the analyzed species could be totally new to science. These species could have been undetected until now because of the difficulties in distinguishing them from others that are morphologically very similar. The results of this research will be very useful to guide future studies of butterfly biodiversity and improving their conservation, establishing priorities, and avoiding the mixing up of divergent lineages. "Knowing the exact number of species and differentiating them is essential for their protection," says the article’s senior author Dr. Roger Vila, Institut de Biologia Evolutiva (CSIC-Universitat Pompeu Fabra, Barcelona, Spain). The CSIC is the Spanish National Research Council. Also, adds Dr.