Scientists discover new mechanisms by which RNA drugs can control gene activity

 In continuation of my update on RNAi

Short strands of nucleic acids, called small RNAs, can be used for targeted gene silencing, making them attractive drug candidates. These small RNAs block gene expression through multiple RNA interference (RNAi) pathways, including two newly discovered pathways in which small RNAs bind to Argonaute proteins or other forms of RNA present in the cell nucleus, such as long non-coding RNAs and pre-mRNA. 

Keith T. Gagnon, PhD, and David R. Corey, PhD, University of Texas Southwestern Medical Center, in Dallas, review common features shared by RNAi pathways for controlling gene expression and focus in detail on the potential for Argonaute-RNA complexes in gene regulation and other exciting new options for targeting emerging forms of non-coding RNAs and pre-mRNAs in the article "Argonaute and the Nuclear RNAs: New Pathways for RNA Mediated Control of Gene Expression." 

"The field of RNA mediated control of gene expression is rapidly evolving and the article by Gagnon and Corey provides a highly informative and up to date review of this exciting and often surprising area of biomedical research. We are delighted to publish this important review for the field," says Co-Editor-in-Chief Bruce A. Sullenger, PhD, Duke Translational Research Institute, Duke University Medical Center, Durham, NC.

Ref : http://www.liebertpub.com/global/pressrelease/new-rna-based-therapeutic-strategies-for-controlling-gene-expression/987/

Redesigned Vancomycin As Potent Antimicrobial Activity Against Vancomycin-Resistant Bacteria...

In continuation of my update on vancomycin....

A team of scientists from The Scripps Research Institute has successfully reengineered an important antibiotic (Vancomycin)  to kill the   deadliest antibiotic-resistant bacteria. The researchers claim that compound could one day be used clinically to treat patients with life-threatening and highly resistant bacterial infections. The compound synthesized is  an  analogue of the well-known commercial antibiotic vancomycin.

Vancomycin normally works by grabbing hold of and sequestering the bacterial cell-wall making machinery, a peptidoglycan (carbohydrate and peptide containing molecule). Only Gram-positive bacteria have a cell wall, which is a membrane on the cell's outer surface. Unfortunately, bacteria have found a way to alter the peptidoglycan in such a way that the antibiotic can no longer grab hold. Researchers claim that,  the new vancomycin analogue can grab hold of the mutant peptidoglycan, and again prevent the bacteria from making the cell wall and killing the resistant bacteria. But what is so remarkable about the design is that the redesigned antibiotic maintains its ability to bind the wild type peptidoglycan as well.

New compound has an amidine (an iminium, RC=NH+ linked to a nitrogen, N) instead of an amide at a key position buried in the interior of the natural product. I appreciate the idea and the simplicity in achieving the target functional group.

Researchers add that, although it is still at its early stages and there is much work ahead.In my opinion it is a good beginning...

Ref : A Redesigned Vancomycin Engineered for Duald-Ala-d-Ala andd-Ala-d-Lac Binding Exhibits Potent Antimicrobial Activity Against Vancomycin-Resistant Bacteria

Liquorice root for antibiotic-resistant infections resulting from severe burns...

Liquorice root candy, or properly Glycyrrhiza glabra, is the dried root  of the liquorice plant (see pictures - credit : wikipedia), which is eaten as a candy. It is also used in traditional Chinese medicine, as well as in the traditional medicines of Japan, Korea, Vietnam, and other Asian nations (In India ಯಷ್ಠಿಮಧು/ಅತಿಮಧುರ (in kannada & मुलहठी in hindi). The extract of the liquorice root is one of the main ingredients in liquorice confectionery. Liquorice root can be shredded and added to boiling water to create liquorice root tea. Liquorice root has been traditionally used as a herbal remedy against different symptoms, such as cough and catarrh. People with heart conditions or high blood pressure should avoid ingesting extensive amounts of liquorice, as it can further heighten blood pressure and lead to stroke.

Though liquorice root has also been reported to speed the healing of canker sores, now researchers from University of Texas Medical Branch and Shriners Hospitals for Children have come up with more interesting findings, that is root can be used to treat antibiotic-resistant infections resulting from severe burns. They found that in burned mice, glycyrrhizin improved the ability of damaged skin to create small proteins that serve as the first line of defense against infection. These proteins, called antimicrobial peptides, work by puncturing the cell membranes of bacteria similar to how pins pop balloons. As per the claim by the researchers lead by Dr. Fujio Suzuki, more research is necessary to determine if this finding would have any implications for people with cystic fibrosis, who can develop Pseudomonas aeruginosa infections in their lungs.

Ref : http://www.jleukbio.org/cgi/content/abstract/87/1/35