Protein expression from exogenous mRNA: uptake by receptor-mediated endocytosis and trafficking via the lysosomal...

Area of Science:

• Molecular Biology
• Biotechnology
• Drug Delivery

Background:

• DNA-based therapies face limitations due to insertional mutagenesis and malignancy risks.
• Messenger RNA (mRNA) presents a transient and safer alternative for genetic therapies.
• Understanding mRNA cellular uptake and trafficking is crucial for developing effective mRNA therapeutics.

Purpose of the Study:

• To investigate the cellular uptake mechanisms of naked mRNA.
• To determine the intracellular fate and trafficking pathways of internalized mRNA.
• To identify receptors involved in mRNA internalization.

Main Methods:

• Assessed cell-type, dose, and energy dependence of mRNA internalization.
• Utilized pathway and cellular compartment markers to track mRNA.
• Employed competitor-based assays to identify involved receptors.

Main Results:

• All tested cell types demonstrated uptake and expression of naked mRNA.
• mRNA internalization primarily occurred via caveolae/lipid raft domains, involving scavenger receptors.
• Internalized mRNA accumulated in lysosomes, with a portion escaping to the cytosol for protein synthesis.

Conclusions:

• Provides novel insights into the cellular internalization and trafficking of exogenous mRNA.
• Identifies key cellular mechanisms and receptors involved in mRNA uptake.
• Findings significantly advance the development of future mRNA-based therapies.