MK4 Repositioning for IAHSP: Overcoming In Vivo Data Gaps through In Silico Refinement and In Vitro Validation

Area of Science:

• Neuroscience
• Genetics
• Pharmacology

Background:

• Infantile-onset Ascending Hereditary Spastic Paralysis (IAHSP) is an ultrarare, autosomal recessive neurodegenerative disorder.
• Mutations in the ALS2 gene, encoding ALSIN protein, cause IAHSP.
• Previous work suggested Menatetrenone (MK4) as a personalized therapy for a specific IAHSP mutation (R1611W).

Purpose of the Study:

• To investigate the cellular efficacy of Menatetrenone (MK4) for IAHSP in the absence of in vivo models.
• To establish and characterize a patient-derived cell line for IAHSP drug discovery.
• To identify and validate cellular markers for IAHSP and MK4 treatment response.

Main Methods:

• Molecular Dynamics (MD) simulations to analyze MK4 interaction with the R1611W ALSIN mutation.
• Establishment and characterization of skin fibroblast cell lines from an IAHSP patient.
• Advanced microscopy and automated image analysis to identify mitochondrial phenotypes and establish a cell marker (Mean Branch Diameter).

Main Results:

• MD simulations confirmed MK4 interaction with the mutation site.
• IAHSP fibroblasts exhibited elevated oxidative stress and a distinct mitochondrial phenotype (altered Mean Branch Diameter).
• MK4 treatment rescued the Mean Branch Diameter and ALSIN levels in patient-derived fibroblasts, demonstrating cellular efficacy.

Conclusions:

• This study presents an integrated computational and cell-based approach for rare disease drug discovery.
• A patient-derived fibroblast model with a validated mitochondrial marker (Mean Branch Diameter) can assess IAHSP therapeutic efficacy.
• MK4 shows potential as a therapeutic agent for IAHSP, providing a framework for preclinical drug discovery in monogenic disorders.