In:
Neurology Genetics, Ovid Technologies (Wolters Kluwer Health), Vol. 6, No. 4 ( 2020-08), p. e484-
Abstract:
We aimed to determine whether 3D imaging reconstruction allows identifying molecular:clinical associations in myotonic dystrophy type 1 (DM1). Methods We obtained myoblasts from 6 patients with DM1 and 6 controls. We measured cytosine-thymine-guanine (CTG) expansion and detected RNA foci and muscleblind like 1 (MBNL1) through 3D reconstruction. We studied dystrophia myotonica protein kinase (DMPK) expression and splicing alterations of MBNL1, insulin receptor, and sarcoplasmic reticulum Ca(2+)-ATPase 1. Results Three-dimensional analysis showed that RNA foci (nuclear and/or cytoplasmic) were present in 45%–100% of DM1-derived myoblasts we studied (range: 0–6 foci per cell). RNA foci represented 〈 0.6% of the total myoblast nuclear volume. CTG expansion size was associated with the number of RNA foci per myoblast ( r = 0.876 [95% confidence interval 0.222–0.986]) as well as with the number of cytoplasmic RNA foci ( r = 0.943 [0.559–0.994]). Although MBNL1 colocalized with RNA foci in all DM1 myoblast cell lines, colocalization only accounted for 1% of total MBNL1 expression, with the absence of DM1 alternative splicing patterns. The number of RNA foci was associated with DMPK expression ( r = 0.967 [0.079–0.999]). On the other hand, the number of cytoplasmic RNA foci was correlated with the age at disease onset ( r = −0.818 [−0.979 to 0.019]). Conclusions CTG expansion size modulates RNA foci number in myoblasts derived from patients with DM1. MBNL1 sequestration plays only a minor role in the pathobiology of the disease in these cells. Higher number of cytoplasmic RNA foci is related to an early onset of the disease, a finding that should be corroborated in future studies.
Type of Medium:
Online Resource
ISSN:
2376-7839
DOI:
10.1212/NXG.0000000000000484
Language:
English
Publisher:
Ovid Technologies (Wolters Kluwer Health)
Publication Date:
2020
detail.hit.zdb_id:
2818607-2
