In vivo siRNA delivery in whitefish: siRNA uptake and the efficacy of gene expression silencing

Title : In vivo siRNA delivery in whitefish: siRNA uptake and the efficacy of gene expression silencing

Abstract:

The delivery of therapeutic snippets of RNA (mainly siRNA) to the right cells at the right time is an essential step in the RNA mediated therapeutics, that in fish has not been studied in sufficient detail. Here we report an efficient in vivo delivery of MiRNA92b-3p mimic to whitefish, a Teleost fish with commercial importance. To address this issue, juvenile individuals of whitefish were exposed to synthetic miRNA, miR92b-3p mimic through intraperitoneal injection. After 24 and 48 h of the treatment, blood and livers of the fish were collected to tract uptake of the synthetic miRNA and to assess its specific and off-side effects. qPCR indicated that, within the first 24 h of the treatment, miR92b-3p levels were markedly elevated in the plasma and the liver of the injected fish compared to control fish injected with vehicle solvent only. Furthermore, 48 h after the injection, the mimic abrogated mRNA expression of several genes in the liver, including p53 tumor suppressor and its downstream effector, cdkn1a. Finally, histopathological and ultrastructural analyses did not show any major changes in the livers of the exposed fish, as well as no differences were found in biochemical measurements of the fishes blood between the experimental groups. Together, these results indicate that the miR92b-3p mimic was effectively delivered into the liver of the injected fish, and that the treatment did not cause any distinct off-side effects. The described methodology of miRNA mimic delivery has utility for the study of miRNA-dependent silencing mechanisms and the development of both miRNA diagnostic marker and therapeutic target in fish liver injury.

Audience take away:
The described methodology of miRNA mimic delivery has utility for the study of miRNA-dependent silencing mechanisms in cold-blooded fish .

Biography:

Prof. Brzuzan leads a team that focuses on the role of microRNA in biology and medicine with a special emphasis on toxicology.The team has skills in using both experimental fish (whitefish, rainbow trout) and cell cultures to study perturbations of molecular responses to environmental pollutants. His present interest is in disease states featuring microRNA in drug induced liver toxicity as well as current understanding of microRNAsas therapeutic targets in cancer. He looks also if bioactive cyanobacterial metabolites have molecular abilities to modulate regulatory elements of cell processes (RNA, protein), thus becoming important tools for clarifying the mechanisms of these cell processes and serving as lead structures for the development of new therapeutic agents.