Multiscale modeling uncovers 7q11.23 copy number variation–dependent changes in ribosomal biogenesis and neuronal maturation and excitability
Marija Mihailovich, … , Michela Matteoli, Giuseppe Testa
Marija Mihailovich, … , Michela Matteoli, Giuseppe Testa
Published July 15, 2024
Citation Information: J Clin Invest. 2024;134(14):e168982. https://doi.org/10.1172/JCI168982.
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Research Article Neuroscience

Multiscale modeling uncovers 7q11.23 copy number variation–dependent changes in ribosomal biogenesis and neuronal maturation and excitability

Abstract

Copy number variation (CNV) at 7q11.23 causes Williams-Beuren syndrome (WBS) and 7q microduplication syndrome (7Dup), neurodevelopmental disorders (NDDs) featuring intellectual disability accompanied by symmetrically opposite neurocognitive features. Although significant progress has been made in understanding the molecular mechanisms underlying 7q11.23-related pathophysiology, the propagation of CNV dosage across gene expression layers and their interplay remains elusive. Here we uncovered 7q11.23 dosage–dependent symmetrically opposite dynamics in neuronal differentiation and intrinsic excitability. By integrating transcriptomics, translatomics, and proteomics of patient-derived and isogenic induced neurons, we found that genes related to neuronal transmission follow 7q11.23 dosage and are transcriptionally controlled, while translational factors and ribosomal genes are posttranscriptionally buffered. Consistently, we found phosphorylated RPS6 (p-RPS6) downregulated in WBS and upregulated in 7Dup. Surprisingly, p-4EBP was changed in the opposite direction, reflecting dosage-specific changes in total 4EBP levels. This highlights different dosage-sensitive dyregulations of the mTOR pathway as well as distinct roles of p-RPS6 and p-4EBP during neurogenesis. Our work demonstrates the importance of multiscale disease modeling across molecular and functional layers, uncovers the pathophysiological relevance of ribosomal biogenesis in a paradigmatic pair of NDDs, and uncouples the roles of p-RPS6 and p-4EBP as mechanistically actionable relays in NDDs.

Authors

Marija Mihailovich, Pierre-Luc Germain, Reinald Shyti, Davide Pozzi, Roberta Noberini, Yansheng Liu, Davide Aprile, Erika Tenderini, Flavia Troglio, Sebastiano Trattaro, Sonia Fabris, Ummi Ciptasari, Marco Tullio Rigoli, Nicolò Caporale, Giuseppe D’Agostino, Filippo Mirabella, Alessandro Vitriolo, Daniele Capocefalo, Adrianos Skaros, Agnese Virginia Franchini, Sara Ricciardi, Ida Biunno, Antonino Neri, Nael Nadif Kasri, Tiziana Bonaldi, Rudolf Aebersold, Michela Matteoli, Giuseppe Testa

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Figure 5

Genotype-specific dysregulation of p-RPS6, but not p-4EBP, in 30-day-old iNeurons.

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Genotype-specific dysregulation of p-RPS6, but not p-4EBP, in 30-day-old...
(A) Simplified scheme of mTOR signaling. (B–G) Quantification of Western blot analyses for total RPS6 (B), p-RPS6 S240/S244, and p-RPS6 S235/S236 normalized to RPS6 levels (C and D respectively), 4EBP (E), p-4EBP Thr37/Thr46 (F), and p-4EBP Thr37/Thr46 normalized to 4EBP levels (G). The experiment was done on 6 different iNeuron preparations, differentiated in 2 different rounds of differentiation. (H) Representative Western blot quantification for B–G. Other quantified blots are shown in Supplemental Figure 5. (I and J) Quantification of puromycin incorporation assay (I; n = 5) with representative Western blot (J). Other quantified blots are shown in Supplemental Figure 4G. All data are shown as mean ± SEM. The statistical comparisons were done with 2-way ANOVA followed by Tukey’s multiple-comparison test (B–G) or 1-way ANOVA followed by Tukey’s multiple-comparison test (I). *P < 0.05; **P < 0.01; ***P < 0.001; ****P < 0.0001. Black asterisks indicate significance between treatments, whereas the red asterisks indicate significance between genotypes.