Biunno, I. | bioRxiv Science

bioRxiv2022

7q11.23 CNV alters protein synthesis and REST-mediated neuronal intrinsic excitability

Copy number variations (CNVs) at 7q11.23 cause Williams-Beuren (WBS) and 7q microduplication syndromes (7Dup), two neurodevelopmental disorders with shared and opposite cognitive-behavioral phenotypes. Using patient-derived and isogenic neurons, we integrated transcriptomics, translatomics and proteomics to elucidate the molecular underpinnings of this dosage effect. We found that 7q11.23 CNVs cause opposite alterations in neuronal differentiation and excitability. Genes related to neuronal transmission chiefly followed 7q11.23 dosage and appeared transcriptionally controlled, while translation and ribosomal protein genes followed the opposite trend and were post-transcriptionally buffered. Mechanistically, we uncovered REST regulon as a key mediator of observed phenotypes and rescued transcriptional and excitability alterations through REST inhibition. We identified downregulation of global protein synthesis, mGLUR5 and ERK-mTOR pathways activity in steady-state in both WBS and 7Dup, whereas BDNF stimulation rescued them specifically in 7Dup. Overall, we show that 7q11.23 CNVs alter protein synthesis and neuronal firing-established molecular and cellular phenotypes of neurodevelopmental disorders. Graphical abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=200 SRC="FIGDIR/small/511483v1_ufig1.gif" ALT="Figure 1"> View larger version (40K): org.highwire.dtl.DTLVardef@1b0fa99org.highwire.dtl.DTLVardef@146624org.highwire.dtl.DTLVardef@13dc89aorg.highwire.dtl.DTLVardef@13d098f_HPS_FORMAT_FIGEXP M_FIG C_FIG

neuroscience↗

bioRxiv2022

ANKRD26 is a new regulator of type I cytokine receptor signaling in normal and pathological hematopoiesis

Sustained ANKRD26 expression associated with germline ANKRD26 mutations causes Thrombocytopenia 2 (THC2), an inherited platelet disorder associated with leukemia predisposition. Some of those patients present also erythrocytosis and/or leukocytosis. Using multiple human-relevant in vitro models (cell lines, primary patient cells and patient-derived iPSCs) we demonstrate for the first time that ANKRD26 is expressed during the early steps of erythroid, megakaryocyte and granulocyte differentiation, and is necessary for progenitor proliferation. As differentiation progresses, ANKRD26 expression is progressively silenced, to complete the cellular maturation of the three myeloid lineages. In primary cells, abnormal ANKRD26 expression in committed progenitors directly impacts the proliferation/differentiation balance for these three cell types. We show that ANKRD26 interacts with and crucially modulates the activity of MPL, EPOR and G-CSFR, three homodimeric type I cytokine receptors that regulate blood cell production. Higher than normal levels of ANKRD26 prevent the receptor internalization, which leads to increased signaling and cytokine hypersensitivity. Altogether these findings show that ANKRD26 overexpression or the absence of its silencing during differentiation are responsible for myeloid blood cell abnormalities in THC2 patients.

cell biology↗