Silencing microRNA by interfering nanoparticles in mice

Area of Science:

• Biochemistry
• Molecular Biology
• Pharmacology

Background:

• MicroRNAs (miRNAs) are key regulators of gene expression with roles in numerous biological processes.
• Disease-associated miRNAs present therapeutic targets, and their function can be inhibited by antisense oligonucleotides (anti-miRs).

Purpose of the Study:

• To evaluate the efficacy of systemically delivered, chemically stabilized anti-miR-122 complexed with interfering nanoparticles (iNOPs) for silencing miR-122 in vivo.
• To assess the impact of miR-122 silencing on liver gene expression and plasma cholesterol levels.
• To determine the duration of silencing and potential immune response to the anti-miR-122/iNOP complex.

Main Methods:

• Systemic intravenous administration of chemically modified anti-miR-122 complexed with iNOP-7 in mice.
• Quantification of miR-122 silencing in the liver.
• Analysis of liver gene expression profiles.
• Measurement of plasma cholesterol levels.
• Assessment of immune response.

Main Results:

• Intravenous administration of 2 mg/kg anti-miR-122/iNOP-7 achieved 83.2 ± 3.2% specific silencing of miR-122 in the liver.
• miR-122 silencing led to significant regulation of gene expression in the liver and a reduction in plasma cholesterol.
• The observed silencing effect was long-lasting and did not elicit an observable immune response.

Conclusions:

• Interfering nanoparticles (iNOPs) provide an effective delivery system for anti-miRs, enabling specific targeting and silencing of miRNAs in vivo.
• This approach demonstrates therapeutic potential for treating miR-122-related conditions, offering a clinically acceptable and affordable method.