RNAi targeting LMAN1-MCFD2 complex promotes anticoagulation in mice

Area of Science:

• Molecular Biology
• Genetics
• Pharmacology

Background:

• Combined deficiency of coagulation factors V (FV) and VIII (FVIII) is a rare bleeding disorder linked to LMAN1 or MCFD2 gene variants.
• Inhibiting the LMAN1-MCFD2 complex to reduce FVIII levels presents a potential new anticoagulant approach.

Purpose of the Study:

• To investigate the therapeutic potential of RNA interference (RNAi) targeting LMAN1 and MCFD2 for anticoagulation.
• To develop a novel anticoagulant therapy by reducing FVIII levels through LMAN1-MCFD2 complex inhibition.

Main Methods:

• Designed and screened cross-homologous siRNA sequences targeting LMAN1 or MCFD2 transcripts.
• Chemically modified optimal siRNAs with N-acetylgalactosamine (GalNAc) for targeted liver delivery.
• Assessed LMAN1 and MCFD2 expression, coagulation function (APTT), FVIII activity, and bleeding in mice.

Main Results:

• GalNAc-conjugated siRNAs (GalNAc-LMAN1, GalNAc-MCFD2) demonstrated effective and sustained inhibition of LMAN1 and MCFD2 mRNA.
• Significant reduction in LMAN1 and MCFD2 mRNA levels observed post-injection.
• Repeated administration prolonged APTT and markedly decreased FVIII activity without significantly increasing bleeding in mice.

Conclusions:

• RNAi therapy targeting the LMAN1-MCFD2 complex is an effective strategy for anticoagulation.
• This approach offers a viable option for developing new anticoagulant drugs.
• Further evaluation in thrombophilic models is needed to assess benefits and bleeding risks.