Smith–Magenis syndrome protein RAI1 regulates body weight homeostasis through hypothalamic BDNF-producing neurons and neurotrophin downstream signalling
- Department of Neurology and Neurosurgery, Centre for Research in Neuroscience, McGill University, Canada
- Brain Repair and Integrative Neuroscience Program, The Research Institute of the McGill University Health Centre, Canada
Figures
Figure 1 with 1 supplement
Rai1 haploinsufficiency disrupts hypothalamic proteomic profile in mice.
(A) ELISA showing that brain-derived neurotrophic factor (BDNF) protein levels in hypothalamic tissues were significantly reduced in Smith–Magenis syndrome (SMS) mice compared to controls (n = …
Figure 1—figure supplement 1
Differentially expressed proteins in the hypothalamus of Smith–Magenis syndrome (SMS) mice.
A heat map showing hierarchical clustering of differentially expressed proteins in the hypothalamus of SMS mice.
Figure 2 with 4 supplements
RAI1 is required in brain-derived neurotrophic factor (BDNF)-producing cells to regulate energy metabolism.
(A) A schematic diagram showing selective deletion of Rai1 from BDNF-producing cells in mice. (B) Representative images showing that in Ctrl mice (BdnfCre/+; Ai9), many PVHBDNF neurons (magenta) …
Figure 2—figure supplement 1
The BdnfCre allele labels brain-derived neurotrophic factor (BDNF)-producing neurons in the paraventricular nucleus of the hypothalamus.
(A) Schematic showing a transgenic mouse expressing BdnfCre-dependent td-Tomato (Ai9) signals in BDNF-expressing cells. (B–E) Colocalization of BdnfCre-dependent td-Tomato signals with endogenous …
Figure 2—figure supplement 2
RAI1 expression in brain-derived neurotrophic factor (BDNF)-expressing but not oxytocin-expressing magnocellular paraventricular nucleus of the hypothalamus (PVH) neurons.
(A–H) Representative images of DAPI expression (blue, A), oxytocin (green, B), BDNF-producing cells (Ai9 reporter, magenta, C), and RAI1 protein (cyan, D) in the PVH. Scale bar: 25μm. Note that …
Figure 2—figure supplement 3
Ablating Rai1 from the brain-derived neurotrophic factor (BDNF)-producing cells induces body weight gain and defective energy homeostasis.
(A) Schematic representation of the conditional knockout mice carrying either normal Rai1 alleles and the Ai9 reporter in BDNF-producing cells (top) or homozygous Rai1 deletion and the Ai9 reporter …
Figure 2—figure supplement 4
Metabolic profiles of male conditional knockout (cKO) mice lacking RAI1 expression in the brain-derived neurotrophic factor (BDNF)-producing cells.
(A) Male cKO mice gained significantly more weight than Ctrl mice beginning at 15 wk of age. Two-way ANOVA with Šidák’s multiple comparisons test, *p < 0.05, **p<0.01, ****p < 0.0001. Ctrl n = 9, …
Figure 3 with 1 supplement
Rai1 loss reduces intrinsic neuronal excitability and enhances inhibitory synaptic transmission of PVHBDNF neurons.
(A) A representative image showing a patched PVHBDNF neuron labelled by BdnfCre-dependent tdTomato fluorescence signals. (B, C) Representative traces of spontaneous firing of control (black) and …
Figure 3—figure supplement 1
The cellular and synaptic properties of control and Rai1-deficient PVHBDNF neurons.
(A) Representative traces of rebound and rebound repetitive firing of PVHBDNF neurons in control (black) and conditional knockout (cKO) (red). (B) Representative AP waveforms at holding voltages of …
Figure 4 with 1 supplement
Selective Rai1 ablation in PVHBDNF neurons induces obesity.
(A) A schematic showing stereotaxic injection of adeno-associated viruses (AAVs) expressing Cas9 protein and single-guide RNAs targeting Rai1 (sgRai1) to delete Rai1 from the PVHBDNF neurons of BdnfC…
Figure 4—figure supplement 1
Metabolic profile of mice lacking Rai1 in PVHBDNF neurons.
(A) Representative images showing co-expression of virus-infected cells (GFP/green), BdnfCre-dependent Ai9 signals (brain-derived neurotrophic factor [BDNF] cells, magenta), and endogenous RAI1 …
Figure 5 with 2 supplements
LM22A-4 treatment partially alleviates obesity and stereotypic behaviour in adult Smith–Magenis syndrome (SMS) mice.
(A) Representative western blot showing p-AKT, total AKT, histone 3 (H3, a loading control) levels in the hypothalamus of saline-treated Ctrl, saline-treated SMS, and LM22A-4-treated SMS mice. (B) …
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Figure 5—source data 1
Original uncropped western blot images for Figure 5.
- https://cdn.elifesciences.org/articles/90333/elife-90333-fig5-data1-v1.zip
Figure 5—figure supplement 1
LM22A-4 treatment does not disrupt energy homeostasis and repetitive rearing in the Ctrl mice.
(A) LM22A-4 concentration in the hypothalamus and forebrain of Smith–Magenis syndrome (SMS) mice 1 hr (black dots) and 3 hr (red dots) after simultaneous intranasal and IP injections. (B) Four …
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Figure 5—figure supplement 1—source data 1
Original uncropped western blot images for Figure 5—figure supplement 1.
- https://cdn.elifesciences.org/articles/90333/elife-90333-fig5-figsupp1-data1-v1.zip
Figure 5—figure supplement 2
LM22A-4 treatment in adult Smith–Magenis syndrome (SMS) mice is insufficient to improve social interaction deficit.
(A) Schematic showing the tube test that assesses social interaction between stranger mice of different genotypes. (B) 7-week-old Ctrl mice won significantly more than SMS mice before the LM22A-4 …
