The use of double-stranded RNA (dsRNA) to trigger RNA interference and thereby silence matching disease genes is being pursued as a therapeutic approach for many human diseases. However, it is difficult to deliver these RNA-based drugs into human cells. In contrast, when dsRNA is introduced into one cell in plants and in some animals such as the worm C. elegans, genes in distant cells are also silenced due to the transport between cells of forms of dsRNA called mobile RNA. This direct transport of RNA between cells represents a novel form of intercellular signaling that was accidentally discovered as part of gene silencing studies in the worm C. elegans and in plants. How RNA that is transcribed in the nucleus is secreted from animal cells to silence a target gene in distant cells s not well understood. Studies in C. elegans identified conserved proteins required for the uptake of mobile RNAs suggesting that similar mechanisms may exist in other animals, including mammals. Intriguingly, populations of extracellular RNAs have been found in human blood and are being pursued as diagnostic tools to assess the disease state of internal organs, which are presumably the source of such RNAs. The goals of this proposal are to use the tools available in C. elegans to uncover how dsRNA is modified to generate mobile RNAs that are secreted from cells and to analyze genes that control the export of such RNAs from cells. Using available mutants, we will take biochemical and genetic approaches to identify modified dsRNAs and the mobile RNAs that result from them. We will use new mutants we have isolated that are defective in the intercellular transport of RNAs to discover additional genes that control this process and analyze them. The completion of these aims can reveal how RNAs are modified for export from animal cells and can begin to assemble the pathway for intercellular signaling by the direct transport of RNA between animal cells. These studies are also relevant to understand the entirely unknown biology of extracellular RNAs, which can become powerful diagnostic tools for diseases of internal organs. Finally, if we understand what modifications to dsRNA and other cellular machinery enable the efficient entry of mobile RNAs into C. elegans cells, we can design similar modified dsRNAs for efficient delivery into human cells for RNA interference-based therapy.

Public Health Relevance

Gene silencing using RNA interference is being pursued as a therapeutic approach for multiple human diseases. Our work will elucidate how RNAs made during RNA interference in the worm C. elegans move from one cell to another. Understanding these RNAs that can easily enter cells will inform the design of similar RNA- based drugs for effective delivery into human cells and also shed light on the biology of extracellular RNAs found in human blood, which are being pursued as diagnostic reporters of internal disease states.

Agency
National Institute of Health (NIH)
Institute
National Institute of General Medical Sciences (NIGMS)
Type
Research Project (R01)
Project #
5R01GM111457-03
Application #
9128655
Study Section
Molecular Genetics B Study Section (MGB)
Program Officer
Bender, Michael T
Project Start
2014-09-01
Project End
2019-08-31
Budget Start
2016-09-01
Budget End
2017-08-31
Support Year
3
Fiscal Year
2016
Total Cost
Indirect Cost
Name
University of Maryland College Park
Department
Anatomy/Cell Biology
Type
Earth Sciences/Resources
DUNS #
790934285
City
College Park
State
MD
Country
United States
Zip Code
20742
Jose, Antony M (2018) Replicating and Cycling Stores of Information Perpetuate Life. Bioessays 40:e1700161
Raman, Pravrutha; Zaghab, Soriayah M; Traver, Edward C et al. (2017) The double-stranded RNA binding protein RDE-4 can act cell autonomously during feeding RNAi in C. elegans. Nucleic Acids Res 45:8463-8473
Marre, Julia; Jose, Antony (2017) Inheritance of extracellular nutrition and information in Caenorhabditis elegans. Mol Reprod Dev 84:283
Choi, Yun S; Edwards, Lanelle O; DiBello, Aubrey et al. (2017) Removing bias against short sequences enables northern blotting to better complement RNA-seq for the study of small RNAs. Nucleic Acids Res 45:e87
Le, Hai H; Looney, Monika; Strauss, Benjamin et al. (2016) Tissue homogeneity requires inhibition of unequal gene silencing during development. J Cell Biol 214:319-31
Blumenfeld, Andrew L; Jose, Antony M (2016) Reproducible features of small RNAs in C. elegans reveal NU RNAs and provide insights into 22G RNAs and 26G RNAs. RNA 22:184-92
Marré, Julia; Traver, Edward C; Jose, Antony M (2016) Extracellular RNA is transported from one generation to the next in Caenorhabditis elegans. Proc Natl Acad Sci U S A 113:12496-12501
Jose, Antony M (2015) Movement of regulatory RNA between animal cells. Genesis 53:395-416
Devanapally, Sindhuja; Ravikumar, Snusha; Jose, Antony M (2015) Double-stranded RNA made in C. elegans neurons can enter the germline and cause transgenerational gene silencing. Proc Natl Acad Sci U S A 112:2133-8