Riboswitches for Controlled Expression of Therapeutic Transgenes Delivered by Adeno-Associated Viral Vectors.
10 Jun 2021-Pharmaceuticals, policy and law (Multidisciplinary Digital Publishing Institute)-Vol. 14, Iss: 6, pp 554
TL;DR: In this article, the authors discuss the advantages of riboswitches in the context of AAV-delivered gene therapy, the subsets of Riboswitch mechanisms which have been shown to function in human cells and animal models, recent progress in riboswitch isolation and optimization, and several examples of a AAV delivered therapeutic system which might be improved by ribo-witch regulation.
Abstract: Vectors developed from adeno-associated virus (AAV) are powerful tools for in vivo transgene delivery in both humans and animal models, and several AAV-delivered gene therapies are currently approved for clinical use. However, AAV-mediated gene therapy still faces several challenges, including limited vector packaging capacity and the need for a safe, effective method for controlling transgene expression during and after delivery. Riboswitches, RNA elements which control gene expression in response to ligand binding, are attractive candidates for regulating expression of AAV-delivered transgene therapeutics because of their small genomic footprints and non-immunogenicity compared to protein-based expression control systems. In addition, the ligand-sensing aptamer domains of many riboswitches can be exchanged in a modular fashion to allow regulation by a variety of small molecules, proteins, and oligonucleotides. Riboswitches have been used to regulate AAV-delivered transgene therapeutics in animal models, and recently developed screening and selection methods allow rapid isolation of riboswitches with novel ligands and improved performance in mammalian cells. This review discusses the advantages of riboswitches in the context of AAV-delivered gene therapy, the subsets of riboswitch mechanisms which have been shown to function in human cells and animal models, recent progress in riboswitch isolation and optimization, and several examples of AAV-delivered therapeutic systems which might be improved by riboswitch regulation.
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TL;DR: Recent advances that provide a comprehensive (capsid and cargo) AAV toolkit for genetic access to molecularly defined brain cell types are discussed.
Abstract: Recombinant adeno-associated viruses (AAVs) are commonly used gene delivery vehicles for neuroscience research. They have two engineerable features: the capsid (outer protein shell) and cargo (encapsulated genome). These features can be modified to enhance cell type or tissue tropism and control transgene expression, respectively. Several engineered AAV capsids with unique tropisms have been identified, including variants with enhanced central nervous system transduction, cell type specificity, and retrograde transport in neurons. Pairing these AAVs with modern gene regulatory elements and state-of-the-art reporter, sensor, and effector cargo enables highly specific transgene expression for anatomical and functional analyses of brain cells and circuits. Here, we discuss recent advances that provide a comprehensive (capsid and cargo) AAV toolkit for genetic access to molecularly defined brain cell types. Expected final online publication date for the Annual Review of Neuroscience, Volume 45 is July 2022. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.
28 citations
TL;DR: This study integrates two widely used technologies, SHAPE chemical probing of RNA and fragment-based ligand discovery, to craft an innovative strategy for creating small molecules that bind to and modulate the activity of a structured RNA.
Abstract: Significance RNA molecules encode proteins and play numerous regulatory roles in cells. Targeting RNA with small molecules, as is routine with proteins, would create broad opportunities for modulating biology and creating new drugs. However, this opportunity has been difficult to realize because creating novel small molecules that bind RNA, especially using modest resources, is challenging. This study integrates two widely used technologies, SHAPE chemical probing of RNA and fragment-based ligand discovery, to craft an innovative strategy for creating small molecules that bind to and modulate the activity of a structured RNA. The anticipated impact is high because the methods are simple, can be implemented in diverse research and discovery contexts, and lead to realistic druglike molecules.
17 citations
TL;DR: In this paper , the authors focus on the mechanism of ligand-directed conformational changes in one of the most widely distributed riboswitches in bacteria: the cobalamin family.
5 citations
TL;DR: In this paper , a recombinant adeno-associated viral vector-mediated gene therapy aimed at permanently lowering intraocular pressure through de novo biosynthesis of prostaglandin F2α within the anterior chamber was evaluated.
Abstract: Prostaglandin analogs are first-line treatments for open angle glaucoma and while effective at lowering intraocular pressure, they are undermined by patient non-compliance, causing atrophy of the optic nerve and severe visual impairment. Herein, we evaluate the safety and efficacy of a recombinant adeno-associated viral vector-mediated gene therapy aimed at permanently lowering intraocular pressure through de novo biosynthesis of prostaglandin F2α within the anterior chamber. This study demonstrated a dose dependent reduction in intraocular pressure in normotensive Brown Norway rats maintained over 12-months. Crucially, therapy could be temporarily halted through off-type riboswitch activation, reverting intraocular pressure to normal. Longitudinal multimodal imaging, electrophysiology, and post-mortem histology revealed the therapy was well tolerated at low and medium doses, with no major adverse effects to anterior chamber health, offering a promising alternative to current treatment strategies leading to clinically relevant reductions in intraocular pressure without the need for adherence to a daily treatment regimen.
2 citations
TL;DR: This review focuses on how riboswitch regulates the riboflavin biosynthesis pathway in Bacillus subtilis and Lactobacillus plantarum.
1 citations
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