Straightjacket/α2δ3 deregulation is associated with cardiac conduction defects in myotonic dystrophy type 1
- GReD, CNRS UMR6293, INSERM U1103, University of Clermont Auvergne, France
- Osaka University Graduate School of Medicine, Japan
- Imagine Institute, Inserm UMR1163, France
- Centre de Recherche en Myologie, Inserm UMRS974, Sorbonne Universités, Institut de Myologie, France
- Aix-Marseille Univ, CNRS UMR 7288, IBDM, France
Figures
Figure 1 with 3 supplements
Cardiac-specific knockdown of MBNL1 ortholog and overexpression of CELF1 counterpart in Drosophila lead to asynchronous heartbeats.
(A) The adult Drosophila heart expressing Hand-Gal4-driven GFP (Hand>GFP). Note that this Gal4 line drives expression exclusively in the heart. Arrows indicate cardiomyocytes (CM) and pericardial …
Figure 1—figure supplement 1
Bru-3 and Mbl are expressed in the adult fly heart and their transcript and protein levels are affected in Hand>Bru-3 and Hand>MblRNAi flies.
(A–B) RT-qPCR analyses of Bru-3 overexpression and Mbl attenuation in the adult hearts from Hand>Bru-3 (A) and Hand>MblRNAi (B) flies. Three biological replicates (n = 10–12 hearts per replicate) …
Figure 1—figure supplement 2
Effect of simultaneous cardiac attenuation of Mbl and overexpression of Bru-3 on conduction defects.
Barplot graph showing percentage of flies with conduction defects. Note a moderate additive effect of simultaneous attenuation of Mbl and overexpression of Bru-3. Number of fly hearts tested (n) is …
Figure 1—video 1
An example of asynchronous heartbeat phenotype observed in Hand>MblRNAi context.
High-speed 20 s time-lapse movie.
Figure 2
Cardiac-specific transcriptional profiling using TU-tagging method.
(A) Pipeline of heart-targeted transcriptional profiling using TU-tagging. Note that Gal4- inducible UPRT transgene (UAS-UPRT) has been combined with UAS-MblRNAi and with UAS-Bru-3 for the purpose …
Figure 3 with 2 supplements
Heart-specific transcriptional profiling of DM1 flies identifies deregulation of genes controlling cellular calcium level.
(A) Venn diagrams of genes deregulated in Hand>UPRT;MblRNAi and in Hand>UPRT;Bru-3 contexts (FC > 1.7) followed by heatmap of commonly deregulated genes. (B) Genemania interaction network of …
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Figure 3—source data 1
A list of Drosophila genes and their Human orthologs deregulated in both Hand>Bru-3 and Hand>MblRNAi contexts.
Orthology scores were obtained from DIOPT tool (DRSC Integrative Ortholog Prediction Tool) (Hu et al., 2011) which predicts orthologs, based on sequence homology, phylogenetic trees, and functional similarity (www.flyrnai.org/cgi-bin/DRSC_orthologs.pl).
- https://cdn.elifesciences.org/articles/51114/elife-51114-fig3-data1-v1.xlsx
Figure 3—figure supplement 1
Attenuation of inaD, Syn1 and Rgk2 all lead to an increase of diastolic (DD) and systolic (SD) heart diameters.
For each candidate gene effects of attenuation were tested using two different UAS-RNAi lines crossed with Hand-Gal4 driver. More than 20 flies for each genotype were analysed by SOHA. Statistical …
Figure 3—figure supplement 2
The expression levels of CG42617 and CG16868, two additional α2δ protein-coding genes are not affected in the heart of DM1 fly models.
Normalized RNAseq IGV tracks in control (Hand>lacZ) and in pathogenic DM1 contexts (Hand>MblRNAi and Hand>Bru-3) are shown aligned with genomic exon/intron organization of CG42617 (A) and CG16868 (B).
Figure 4
Calcium waves in asynchronous Drosophila heart.
In wild type hearts, calcium waves underlie cardiac contractions so that calcium peaks (arrows) align with the onset of contractions (arrowheads) in both A3 and A4 segments. In contrast, in …
Figure 5 with 2 supplements
Increased cardiac expression of Stj contributes to the conduction defects observed in DM1 fly models.
(A) Stj protein is detected at a low level in cardiomyocytes (CM) but at a higher level in the ventral longitudinal muscles (VLMs) that underlie adult heart tube. Stj in VLMs and in heart …
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Figure 5—source data 1
Corrected total cell fluorescence (CTCF) of Stj signal in circular fibers of cardiomyocytes.
- https://cdn.elifesciences.org/articles/51114/elife-51114-fig5-data1-v1.xlsx
Figure 5—figure supplement 1
Stj protein levels in different genetic contexts visualized by immunostaining.
Stj protein expression (red) in circular fibers of cardiomyocytes in wild-type (wt) (A) and in different genetic contexts (B-E) tested. Circular fibers are visualized with phalloidin staining …
Figure 5—figure supplement 2
stj-RC transcript isoform carrying long 3’UTR and alternatively spliced exon 15 is up regulated in Hand>MblRNAi and in Hand>Bru-3 hearts.
(A) RT-qPCR probes for stj-RC specific exon 15 and for total stj transcripts are indicated on the scheme. (B) RT-qPCR analysis of stj-RC and total stj transcript levels in control (Hand>lacZ) fly …
Figure 6 with 1 supplement
Increased cardiac expression of Straightjacket human ortholog α2δ3 is associated with conduction defects in DM1 patients.
(A) In mouse, α2δ3 protein is detected at a high level in atrial cardiac cells and at a low level in ventricles. LV denotes left ventricle. Scale bars, 100 mm. (B) RT-qPCR analysis of mouse α2δ3 …
Figure 6—figure supplement 1
RT-qPCR analysis showing that Cav1.2 transcripts are elevated in human cardiac samples from DM1 patients with conduction defects.
Tables
Key resources table
| 1 | Reagent type (species) or resource | Designation | Source or reference | Identifiers | Additional information |
|---|---|---|---|---|---|
| 2 | Gene (D. melanogaster) | stj | FLYB: FBgn0261041 | ||
| 3 | Gene (D. melanogaster) | mbl | FLYB: FBgn0265487 | ||
| 4 | Gene (D. melanogaster) | bru3 | FLYB: FBgn0264001 | ||
| 5 | Genetic reagent (D. melanogaster) | UAS-stj | FlyORF Zurich ORFeome Project | FlyORF ID: F001252 | |
| 6 | Genetic reagent (D. melanogaster) | stj TRIP | Bloomington Drosophila Stock Center | RRID:BDSC25807 | RNAi line |
| 7 | Genetic reagent (D. melanogaster) | Mbl RNAi | VDRC Vienna Drosophila Resource Center | VDRC: GD 28732 | RNAi line |
| 8 | Genetic reagent (D. melanogaster) | P{XP}bru3d09837 | Exelixis at Harvard Medical School | Harvard: d09837 | UAS carrying P element insertion line |
| 9 | Genetic reagent (D. melanogaster) | UAS-GFP | Bloomington Drosophila Stock Center | RRID:BDSC_32201 | |
| 10 | Genetic reagent (D. melanogaster) | UAS-HA-UPRT | Bloomington Drosophila Stock Center | RRID:BDSC_27604 | |
| 11 | Genetic reagent (D. melanogaster) | UAS-lacZ | Bloomington Drosophila Stock Center | RRID:BDSC_1776 | |
| 12 | Genetic reagent (D. melanogaster) | UAS-GCaMP3 | Bloomington Drosophila Stock Center | RRID:BDSC_32116 | |
| 13 | Genetic reagent (D. melanogaster) | Ca-alpha1D TRIP | Bloomington Drosophila Stock Center | RRID:BDSC_25830 | RNAi line |
| 14 | Genetic reagent (D. melanogaster) | Rgk2 TRIP | Bloomington Drosophila Stock Center | RRID:BDSC_65932 | RNAi line |
| 15 | Genetic reagent (D. melanogaster) | Rgk2 RNAi | VDRC Vienna Drosophila Resource Center | VDRC: GD44611 | RNAi line |
| 16 | Genetic reagent (D. melanogaster) | Syn1 RNAi | VDRC Vienna Drosophila Resource Center | VDRC: GD27893 | RNAi line |
| 17 | Genetic reagent (D. melanogaster) | Syn1 RNAi | Bloomington Drosophila Stock Center | RRID: BDSC_27504 | RNAi line |
| 18 | Genetic reagent (D. melanogaster) | inaD RNAi | VDRC Vienna Drosophila Resource Center | VDRC: GD26211 (unavailable) | RNAi line |
| 19 | Genetic reagent (D. melanogaster) | inaD RNAi | VDRC Vienna Drosophila Resource Center | VDRC: 330227 | RNAi line |
| 20 | Genetic reagent (D. melanogaster) | Hand-GAL4 | Laurent Perrin, TAGC, Marseille, France | GAL4 driver line | |
| 21 | Genetic reagent (D. melanogaster) | TinCΔ4-GAL4 | Rolf Bodmer, SBPMD Institute, San Diego, US | GAL4 driver line | |
| 22 | Antibody | anti-Stj | Hugo Bellen, Baylor College of Medicine, Huston, USA | guinea pig polyclonal | Use 1:500 (IHC) |
| 23 | Antibody | anti-α2δ3 | Greg Neely, University of Sidney, Australia | rabbit polyclonal | Use 1:200 (IHC) |
| 24 | Antibody | anti-α2δ3 | GeneTex | GTX16618 - rabbit polyclonal | Use 1:500 (WB) |
| 25 | Antibody | anti-Bru3 | Millegen, Toulouse, France | rabbit polyclonal | Use 1:1000 (IHC) |
| 26 | Antibody | anti-Mbl | Darren Monckton, Glasgow, UK | sheep polyclonal | Use 1:200 (IHC) |
| 27 | Antibody | anti-GFP | Abcam | ab5450 – goat polyclonal | Use 1:500 (IHC) |
| 28 | Antibody | Anti-GAPDH | Sigma Aldrich | SAB2108266 – rabbit polyclonal | Use 1:3000 (WB) |
