Reversal of pathology in CHMP2B-mediated frontotemporal dementia patient cells using RNA interference.
BACKGROUND
Frontotemporal dementia is the second most common form of young-onset dementia after Alzheimer's disease, and several genetic forms of frontotemporal dementia are known. A rare genetic variant is caused by a point mutation in the CHMP2B gene. CHMP2B is a component of the ESCRT-III complex, which is involved in endosomal trafficking of proteins targeted for degradation in lysosomes. Mutations in CHMP2B result in abnormal endosomal structures in patient fibroblasts and patient brains, probably through a gain-of-function mechanism, suggesting that the endosomal pathway plays a central role in the pathogenesis of the disease.


METHODS
In the present study, we used lentiviral vectors to efficiently knockdown CHMP2B by delivering microRNA embedded small hairpin RNAs.


RESULTS
We show that CHMP2B can be efficiently knocked down in patient fibroblasts using an RNA interference approach and that the knockdown causes reversal of the abnormal endosomal phenotype observed in patient fibroblasts.


CONCLUSIONS
This is the first description of a treatment that reverses the cellular pathology caused by mutant CHMP2B and suggests that RNA interference might be a feasible therapeutic strategy. Furthermore, it provides the first proof of a direct link between the disease-causing mutation and the cellular phenotype in cells originating from CHMP2B mutation patients.
Danish Dementia Research Centre, Department of Neurology, Rigshospitalet, Copenhagen University Hospital, Denmark. troelsn@sund.ku.dk
Troels Tolstrup
TT
Nielsen
Sarah
S
Mizielinska
Lis
L
Hasholt
Adrian M
AM
Isaacs
Jørgen E
JE
Nielsen
D000704:Analysis of Variance; D002478:Cells, Cultured; D056827:Endosomal Sorting Complexes Required for Transport / Q000235:genetics* / Q000378:metabolism; D011992:Endosomes / Q000378:metabolism / Q000473:pathology; D005347:Fibroblasts / Q000378:metabolism / Q000473:pathology; D057180:Frontotemporal Dementia / Q000235:genetics / Q000473:pathology / Q000628:therapy*; D055785:Gene Knockdown Techniques; D015316:Genetic Therapy; D005822:Genetic Vectors; D006801:Humans; D016086:Lentivirus / Q000235:genetics; D010641:Phenotype; D034622:RNA Interference; D034741:RNA, Small Interfering / Q000235:genetics; D060149:Tetraspanin 30 / Q000378:metabolism; D014158:Transcription, Genetic
C554586:CD63 protein, human; C503812:CHMP2B protein, human; D056827:Endosomal Sorting Complexes Required for Transport; D034741:RNA, Small Interfering; D060149:Tetraspanin 30