RNA interference targeting cathepsin B of the carcinogenic liver fluke, Opisthorchis viverrini

Area of Science:

• Parasitology
• Molecular Biology
• Functional Genomics

Background:

• Functional genomics data is lacking for Opisthorchis viverrini and Clonorchis sinensis, important fish-borne trematodes.
• Understanding gene function is crucial for developing control strategies against these neglected tropical disease pathogens.

Purpose of the Study:

• To establish methods for introducing nucleic acids into O. viverrini.
• To demonstrate the feasibility of RNA interference (RNAi) in O. viverrini.
• To investigate the potential for functional genomics in O. viverrini.

Main Methods:

• Adult O. viverrini worms were subjected to square wave electroporation with Cy3-labeled small interfering RNA (siRNA).
• siRNA delivery was confirmed by fluorescence microscopy at 24 and 48 hours post-electroporation.
• Double-stranded RNA targeting cathepsin B was used to induce RNAi, and its effects on mRNA levels and enzyme activity were assessed.

Main Results:

• Electroporation successfully introduced Cy3-labeled siRNA into O. viverrini, with fluorescence observed in various tissues including the gut and reproductive organs.
• Electroporation was well-tolerated by the parasites.
• RNAi targeting cathepsin B resulted in a significant reduction in both specific mRNA levels and cathepsin B activity.
• This study represents the first report of reporter gene introduction and experimental RNAi in O. viverrini.

Conclusions:

• An intact RNA interference pathway exists in O. viverrini.
• Electroporation is a viable method for introducing nucleic acids and performing functional genomics in O. viverrini.
• These findings provide a foundation for future research into gene function and potential therapeutic targets in this important parasite.