Abstract Details

Title Kinase Inhibitors Improve Neurofilament Distribution in CMT2E Human Motor Neuron Axons

Topic Neuromuscular and Clinical Neurophysiology (EMG)

Presentation(s) S58 - Therapeutics in Neuromuscular Disorders (2:28 PM-2:39 PM)

Poster/Presentation
Number 009

Background Mutations in the neurofilament light chain (NFL) gene cause autosomal dominant axonal Charcot-Marie-Tooth neuropathy (CMT2E). NFL is a major component of the neuronal cytoskeleton, providing structural support for the axon and regulating axon diameter. Despite the significant advances in understanding its pathophysiology, there is still no effective, disease-modifying therapy for CMT2E.

Objective To develop a new tridimensional human in vitro system to investigate disease mechanisms and identify potential candidates for therapy development for CMT2E.

Design/Methods Three CMT2E patient-derived as well as three unaffected control motor neurons were cultured in suspension until they formed neurospheres which, when platted, allowed for robust radial axonal growth. Neurofilament axonal distribution was studied by immunostaining.

Results Immunostaining of CMT2E neurospheres with NFL and TUBB3 antibodies revealed numerous areas of NFL accumulation in motor axons from three different patients with N98S CMT2E, but not on four healthy controls, one CMT2A patient and one E396K CMT2E patient (p=0.001). Areas of NFL accumulation were also immunopositive for NFH, pNFH and NFM, demonstrating co-localization of the three neurofilament subtypes within the axonal deposits. In proof-of-concept experiments to evaluate the use of this platform to identify compounds that could reduce the number of axonal NFL deposits in N98S CMT2E motor neurons, we tested three different kinase inhibitors from the University of Miami Center for Therapeutic Innovation library and identify one kinase inhibitor that promoted a 50% reduction in the normalized number of neurofilament deposits at both 25 nM (2.262±0.06 deposits/cm²of axon area) and 250 nM (2.99 ±0.506 deposits/cm²of axon area) doses when compared to vehicle (5.192 ±0.07 deposits/cm²of axon area)(p=0.0011). A second kinase inhibitor with a similar profile was also identified.

Conclusions

We developed a human in vitro system to support drug screening for CMT2E and identified two candidate kinase inhibitors with potential for further development as a therapy for CMT2E.

Authors/Disclosures
Mario A. Saporta, MD, PhD, FAAN (University of Miami) PRESENTER	Dr. Saporta has received personal compensation in the range of $5,000-$9,999 for serving as a Consultant for SwanBio. Dr. Saporta has received personal compensation in the range of $5,000-$9,999 for serving as a Consultant for Pharnext. Dr. Saporta has received personal compensation in the range of $5,000-$9,999 for serving as a Consultant for Applied Therapeutics.
	No disclosure on file
	No disclosure on file
Adriana Rebelo	No disclosure on file
Stephan Zuchner, MD, FAAN (University of Miami School of Medicine)	Dr. Zuchner has received personal compensation in the range of $500-$4,999 for serving as a Consultant for Applied Therapeutics. The institution of Dr. Zuchner has received research support from Muscular Dystrophy Association. The institution of Dr. Zuchner has received research support from CMT Association. Dr. Zuchner has received intellectual property interests from a discovery or technology relating to health care.

��ɫ��

��ɫ��