scholarly journals The Down syndrome critical region protein TTC3 inhibits neuronal differentiation via RhoA and Citron kinase

2007 ◽  
Vol 120 (11) ◽  
pp. 1859-1867 ◽  
Author(s):  
G. Berto ◽  
P. Camera ◽  
C. Fusco ◽  
S. Imarisio ◽  
C. Ambrogio ◽  
...  
Keyword(s):  
Down Syndrome ◽  
Neuronal Differentiation ◽  
Critical Region ◽  
Citron Kinase

scholarly journals Human Trisomic iPSCs from Down Syndrome Fibroblasts Manifest Mitochondrial Alterations Early during Neuronal Differentiation

Biology ◽  
2021 ◽  
Vol 10 (7) ◽  
pp. 609
Author(s):  
Nunzia Mollo ◽  
Matteo Esposito ◽  
Miriam Aurilia ◽  
Roberta Scognamiglio ◽  
Rossella Accarino ◽  
...  
Keyword(s):  
Down Syndrome ◽  
Mitochondrial Dysfunction ◽  
Neuronal Differentiation ◽  
Expression Profiles ◽  
Meta Analysis ◽  
Atp Synthesis ◽  
Differentiation Markers ◽  
Differentiation Potential ◽  
Atp Production ◽  
Mitochondrial Alterations

Background: The presence of mitochondrial alterations in Down syndrome suggests that it might affect neuronal differentiation. We established a model of trisomic iPSCs, differentiating into neural precursor cells (NPCs) to monitor the occurrence of differentiation defects and mitochondrial dysfunction. Methods: Isogenic trisomic and euploid iPSCs were differentiated into NPCs in monolayer cultures using the dual-SMAD inhibition protocol. Expression of pluripotency and neural differentiation genes was assessed by qRT-PCR and immunofluorescence. Meta-analysis of expression data was performed on iPSCs. Mitochondrial Ca2+, reactive oxygen species (ROS) and ATP production were investigated using fluorescent probes. Oxygen consumption rate (OCR) was determined by Seahorse Analyzer. Results: NPCs at day 7 of induction uniformly expressed the differentiation markers PAX6, SOX2 and NESTIN but not the stemness marker OCT4. At day 21, trisomic NPCs expressed higher levels of typical glial differentiation genes. Expression profiles indicated that mitochondrial genes were dysregulated in trisomic iPSCs. Trisomic NPCs showed altered mitochondrial Ca2+, reduced OCR and ATP synthesis, and elevated ROS production. Conclusions: Human trisomic iPSCs can be rapidly and efficiently differentiated into NPC monolayers. The trisomic NPCs obtained exhibit greater glial-like differentiation potential than their euploid counterparts and manifest mitochondrial dysfunction as early as day 7 of neuronal differentiation.

scholarly journals Stable DNMT3L overexpression in SH-SY5Y neurons recreates a facet of the genome-wide Down syndrome DNA methylation signature

2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Benjamin I. Laufer ◽  
J. Antonio Gomez ◽  
Julia M. Jianu ◽  
Janine M. LaSalle
Keyword(s):  
Dna Methylation ◽  
Down Syndrome ◽  
Neuronal Differentiation ◽  
Molecular Mechanisms ◽  
Cpg Island ◽  
Differential Methylation ◽  
Chromosome 21 ◽  
Pairwise Comparisons ◽  
Genome Wide ◽  
A Genome

Abstract Background Down syndrome (DS) is characterized by a genome-wide profile of differential DNA methylation that is skewed towards hypermethylation in most tissues, including brain, and includes pan-tissue differential methylation. The molecular mechanisms involve the overexpression of genes related to DNA methylation on chromosome 21. Here, we stably overexpressed the chromosome 21 gene DNA methyltransferase 3L (DNMT3L) in the human SH-SY5Y neuroblastoma cell line and assayed DNA methylation at over 26 million CpGs by whole genome bisulfite sequencing (WGBS) at three different developmental phases (undifferentiated, differentiating, and differentiated). Results DNMT3L overexpression resulted in global CpG and CpG island hypermethylation as well as thousands of differentially methylated regions (DMRs). The DNMT3L DMRs were skewed towards hypermethylation and mapped to genes involved in neurodevelopment, cellular signaling, and gene regulation. Consensus DNMT3L DMRs showed that cell lines clustered by genotype and then differentiation phase, demonstrating sets of common genes affected across neuronal differentiation. The hypermethylated DNMT3L DMRs from all pairwise comparisons were enriched for regions of bivalent chromatin marked by H3K4me3 as well as differentially methylated sites from previous DS studies of diverse tissues. In contrast, the hypomethylated DNMT3L DMRs from all pairwise comparisons displayed a tissue-specific profile enriched for regions of heterochromatin marked by H3K9me3 during embryonic development. Conclusions Taken together, these results support a mechanism whereby regions of bivalent chromatin that lose H3K4me3 during neuronal differentiation are targeted by excess DNMT3L and become hypermethylated. Overall, these findings demonstrate that DNMT3L overexpression during neurodevelopment recreates a facet of the genome-wide DS DNA methylation signature by targeting known genes and gene clusters that display pan-tissue differential methylation in DS.

Proteins encoded by human Down syndrome critical region gene 1-like 2 (DSCR1L2) mRNA and by a novel DSCR1L2 mRNA isoform interact with cardiac troponin I (TNNI3)

Gene ◽  
2006 ◽  
Vol 372 ◽  
pp. 128-136 ◽  
Author(s):  
Silvia Canaider ◽  
Federica Facchin ◽  
Cristiana Griffoni ◽  
Raffaella Casadei ◽  
Lorenza Vitale ◽  
...  
Keyword(s):  
Down Syndrome ◽  
Critical Region ◽  
Cardiac Troponin ◽  
Troponin I ◽  
Cardiac Troponin I ◽  
Region Gene ◽  
Mrna Isoform

scholarly journals Partial trisomy 21 map: Ten cases further supporting the highly restricted Down syndrome critical region (HR‐DSCR) on human chromosome 21

2019 ◽  
Vol 7 (8) ◽  
Author(s):  
Maria Chiara Pelleri ◽  
Elena Cicchini ◽  
Michael B. Petersen ◽  
Lisbeth Tranebjærg ◽  
Teresa Mattina ◽  
...  
Keyword(s):  
Down Syndrome ◽  
Human Chromosome ◽  
Critical Region ◽  
Trisomy 21 ◽  
Partial Trisomy ◽  
Chromosome 21 ◽  
Human Chromosome 21

Reciprocal Regulation of DSCR1 (Down Syndrome Critical Region 1) Expression and NFAT (Nuclear Factor of Activated T Cells) Activation in Megakaryocytes.

Blood ◽  
2007 ◽  
Vol 110 (11) ◽  
pp. 2204-2204
Author(s):  
Satu Kyttaelae ◽  
Ivonne Habermann ◽  
Martin Bornhaeuser ◽  
Gerhard Ehninger ◽  
Alexander Kiani
Keyword(s):  
T Cells ◽  
Down Syndrome ◽  
Critical Region ◽  
Fas Ligand ◽  
Nuclear Translocation ◽  
Specific Inhibitor ◽  
Chromosome 21 ◽  
Nuclear Factor ◽  
Activated T Cells ◽  
Retroviral Transduction

Abstract NFAT (Nuclear Factor of Activated T cells) is a family of calcium-induced, calcineurin-dependent transcription factors, well characterized as central regulators of inducible gene expression in T lymphocytes but now known to function also in several other cell types in various adaptation and differentiation processes. Activation of NFAT by the phosphatase calcineurin is counteracted by several inhibitory kinases and can be completely blocked by the immunosuppressant Cyclosporin A. The Down syndrome critical region 1 (DSCR1; also termed CSP1, MCIP1 or RCAN1) gene belongs to the calcipressin family of endogenous calcineurin inhibitors and is expressed in several isoforms, one of which (isoform C, coded by exons 4–7) has been described to be a transcriptional target for NFAT in striated muscle, endothelial, and neural cells. The DSCR1 gene is located within the Down syndrome critical region of human chromosome 21 and is, together with 200–300 other genes, overexpressed about 1.5-fold in patients with Down syndrome (DS). Previously, dysregulation of NFAT signaling by overexpression of DSCR1 has been implicated in causing various of the pathophysiological features observed in DS patients. Children with DS also suffer from an about 500-fold increased incidence of acute megakaryocytic leukemia; the respective roles of NFAT or DSCR1 in megakaryocytes of either normal individuals or those with DS, however, has not yet been established. Here we show that DSCR1 is upregulated during megakaryocytic differentiation in a lineage-specific manner, and in mature megakaryocytes is further strongly induced by calcineurin stimulation. DSCR1 expression in megakaryocytes is regulated by NFAT, since overexpression of NFATc2 enhances, while overexpression of the specific inhibitor of NFAT activation, VIVIT, suppresses expression of the gene. We further demonstrate that DSCR1 does not only represent an NFAT target in megakaryocytes, but itself acts an inhibitor of NFAT signaling in these cells. Overexpression of DSCR1 in CMK cells as well as in primary megakaryocytes by retroviral transduction profoundly suppressed ionomycin-induced dephosphorylation and nuclear translocation of NFATc2, as well as transactivation of an NFAT-dependent promoter construct. Finally, overexpression of DSCR1 in megakaryocytes markedly downregulated both the constitutive and induced expression of Fas Ligand, a pro-apoptotic gene recently established as a NFAT target in megakaryocytes. Together, these results suggest that DSCR1 acts as an NFAT-induced NFAT inhibitor in megakaryocytes and, when overexpressed, interferes with the expression of NFAT-dependent megakaryocytic genes.

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