# Engineered microRNA scaffolds for potent gene silencing in vivo

## TL;DR

This paper introduces engineered microRNA scaffolds that can effectively silence genes in mice brains, offering a new approach for long-term gene therapy.

## Contribution

The study introduces novel amiRNAs derived from endogenous pri-miRNAs and provides a pipeline for their generation and validation.

## Key findings

- Engineered amiRNAs efficiently silenced target genes in mice brains when delivered via AAV.
- The amiRNAs showed durable and precise gene silencing, outperforming transient siRNA-based therapies.
- A pipeline was developed to generate and validate amiRNAs from endogenous pri-miRNAs.

## Abstract

RNA interference (RNAi) is emerging as a powerful strategy for therapeutic targeting of “undruggable” targets. However, efficacy of currently used siRNA-based therapies is often hindered by transient effects and limited modeling possibilities. Artificial microRNAs (amiRNAs or miRNA scaffolds) present a durable and precise approach to gene silencing, opening new avenues for developing long lasting targeted therapies. In this study, we engineered highly expressed primary miRNAs (pri-miRNAs) with sequence determinants known to enhance processing efficacy and precision. The resulting amiRNAs were extensively tested both in vitro and in vivo and proved to efficiently silence a target gene when virally delivered via adeno-associated virus (AAV) into mice brains. This study provides a set of novel amiRNAs with potential therapeutic application as well as a pipeline to generate and validate novel amiRNAs from endogenous pri-miRNAs.

The online version contains supplementary material available at 10.1038/s41598-025-07061-y.