miR-375 Regulates Extracellular Vesicle Secretion From Giardia duodenalis via Targeting Rab1a

Area of Science:

• Parasitology
• Molecular Biology
• Cell Biology

Background:

• Giardia duodenalis is a major protozoan cause of diarrheal disease.
• No effective vaccines exist, and drug resistance is increasing.
• Extracellular vesicles (GEVs) from G. duodenalis are involved in immune evasion and inflammation, but their biogenesis is poorly understood.

Purpose of the Study:

• To identify microRNAs (miRNAs) targeting Rab1a in G. duodenalis.
• To investigate the role of these miRNAs in regulating GEV biogenesis and secretion.
• To elucidate the molecular mechanisms controlling GEV formation.

Main Methods:

• Purification and characterization of GEVs using TEM, NTA, and Western blotting.
• High-throughput miRNA sequencing to identify candidate miRNAs.
• Dual-luciferase reporter assays to confirm miRNA-target interaction.
• Functional assays to assess the impact of miRNA overexpression on Rab1a expression and GEV secretion.

Main Results:

• miR-375 was identified as a key miRNA targeting the Rab1a 3'UTR.
• miR-375 directly repressed Rab1a expression at both mRNA and protein levels.
• Overexpression of miR-375 significantly reduced GEV secretion from G. duodenalis.

Conclusions:

• Endogenous G. duodenalis miR-375 post-transcriptionally suppresses Rab1a expression.
• This miR-375-Rab1a interaction negatively regulates GEV release.
• The identified regulatory axis provides new insights into GEV biogenesis in G. duodenalis.