scholarly journals A functional screen of translated pancreatic lncRNAs identifies a microprotein-independent role for LINC00261 in endocrine cell differentiation

2020 ◽  
Author(s):  
Bjoern Gaertner ◽  
Sebastiaan van Heesch ◽  
Valentin Schneider-Lunitz ◽  
Jana Felicitas Schulz ◽  
Franziska Witte ◽  
...  
Keyword(s):  
Cell Differentiation ◽  
Endocrine Cell ◽  
Small Scale ◽  
List Type ◽  
Pancreas Development ◽  
Human Pancreas ◽  
Loss Of Function ◽  
Developmentally Regulated ◽  
Small Proteins ◽  
Heterogenous Group

AbstractLong noncoding RNAs (lncRNAs) are a heterogenous group of RNAs, which can encode small proteins. The extent to which developmentally regulated lncRNAs are translated and whether the produced microproteins are relevant for human development is unknown. Here, we show that many lncRNAs in direct vicinity of lineage-determining transcription factors (TFs) are dynamically regulated, predominantly cytosolic, and highly translated during pancreas development. We genetically ablated ten such lncRNAs, most of them translated, and found that nine are dispensable for endocrine cell differentiation. However, deletion of LINC00261 diminishes generation of insulin+ endocrine cells, in a manner independent of the nearby TF FOXA2. Systematic deletion of each of LINC00261’s seven poorly conserved microproteins shows that the RNA, rather than the microproteins, is required for endocrine development. Our work highlights extensive translation of lncRNAs into recently evolved microproteins during human pancreas development and provides a blueprint for dissection of their coding and noncoding roles.Graphical AbstractHighlightsExtensive lncRNA translation and microprotein production during human pancreas developmentA small-scale loss-of-function screen shows most translated lncRNAs are dispensableLINC00261 is highly translated and regulates endocrine cell differentiationDeleting LINC00261’s evolutionary young microproteins reveals no essential roles

scholarly journals MFng Is Dispensable for Mouse Pancreas Development and Function

2009 ◽  
Vol 29 (8) ◽  
pp. 2129-2138 ◽  
Author(s):  
Per Svensson ◽  
Ingela Bergqvist ◽  
Stefan Norlin ◽  
Helena Edlund
Keyword(s):  
Cell Differentiation ◽  
Notch Signaling ◽  
Pancreas Development ◽  
Loss Of Function ◽  
Pancreatic Cell ◽  
Targeted Deletion ◽  
Mouse Pancreas ◽  
Pancreatic Progenitor ◽  
Pancreatic Progenitor Cells ◽  
And Function

ABSTRACT Notch signaling regulates pancreatic cell differentiation, and mutations of various Notch signaling components result in perturbed pancreas development. Members of the Fringe family of β1,3-N-acetylglucosaminyltransferases, Manic Fringe (MFng), Lunatic Fringe (LFng), and Radical Fringe (RFng), modulate Notch signaling, and MFng has been suggested to regulate pancreatic endocrine cell differentiation. We have characterized the expression of the three mouse Fringe genes in the developing mouse pancreas between embryonic days 9 and 14 and show that the expression of MFng colocalized with the proendocrine transcription factor Ngn3. In contrast, the expression of LFng colocalized with the exocrine marker Ptf1a, whereas RFng was not expressed. Moreover, we show that expression of MFng is lost in Ngn3 mutant mice, providing evidence that MFng is genetically downstream of Ngn3. Gain- and loss-of-function analyses of MFng by the generation of mice that overexpress MFng in early pancreatic progenitor cells and mice with a targeted deletion of MFng provide, however, evidence that MFng is dispensable for pancreas development and function, since no pancreatic defects in these mice were observed.

SOX9 regulates endocrine cell differentiation during human fetal pancreas development

2012 ◽  
Vol 44 (1) ◽  
pp. 72-83 ◽  
Author(s):  
Erin McDonald ◽  
Jinming Li ◽  
Mansa Krishnamurthy ◽  
George F. Fellows ◽  
Cynthia G. Goodyer ◽  
...  
Keyword(s):  
Cell Differentiation ◽  
Endocrine Cell ◽  
Pancreas Development ◽  
Fetal Pancreas ◽  
Human Fetal Pancreas

scholarly journals A human ESC-based screen identifies a role for the translated lncRNA LINC00261 in pancreatic endocrine differentiation

eLife ◽  
2020 ◽  
Vol 9 ◽  
Author(s):  
Bjoern Gaertner ◽  
Sebastiaan van Heesch ◽  
Valentin Schneider-Lunitz ◽  
Jana Felicitas Schulz ◽  
Franziska Witte ◽  
...  
Keyword(s):  
Human Embryonic Stem Cell ◽  
Embryonic Stem ◽  
Noncoding Rnas ◽  
Open Reading Frames ◽  
Developmentally Regulated ◽  
Pancreatic Differentiation ◽  
Endocrine Differentiation ◽  
Small Proteins ◽  
Heterogenous Group ◽  
Reading Frames

Long noncoding RNAs (lncRNAs) are a heterogenous group of RNAs, which can encode small proteins. The extent to which developmentally regulated lncRNAs are translated and whether the produced microproteins are relevant for human development is unknown. Using a human embryonic stem cell (hESC)-based pancreatic differentiation system, we show that many lncRNAs in direct vicinity of lineage-determining transcription factors (TFs) are dynamically regulated, predominantly cytosolic, and highly translated. We genetically ablated ten such lncRNAs, most of them translated, and found that nine are dispensable for pancreatic endocrine cell development. However, deletion of LINC00261 diminishes insulin+ cells, in a manner independent of the nearby TF FOXA2. One-by-one disruption of each of LINC00261's open reading frames suggests that the RNA, rather than the produced microproteins, is required for endocrine development. Our work highlights extensive translation of lncRNAs during hESC pancreatic differentiation and provides a blueprint for dissection of their coding and noncoding roles.

scholarly journals Endocrine Cell Clustering During Human Pancreas Development

2009 ◽  
Vol 57 (9) ◽  
pp. 811-824 ◽  
Author(s):  
Jongmin Jeon ◽  
Mayrin Correa-Medina ◽  
Camillo Ricordi ◽  
Helena Edlund ◽  
Juan A. Diez
Keyword(s):  
Endocrine Cell ◽  
Expression Profiles ◽  
Pregnancy Termination ◽  
Embryonic Stem ◽  
Pancreas Development ◽  
Human Pancreas ◽  
In Vitro Differentiation ◽  
Extrinsic Factors ◽  
Hes Cells

The development of efficient, reproducible protocols for directed in vitro differentiation of human embryonic stem (hES) cells into insulin-producing β cells will benefit greatly from increased knowledge regarding the spatiotemporal expression profile of key instructive factors involved in human endocrine cell generation. Human fetal pancreases 7 to 21 weeks of gestational age, were collected following consent immediately after pregnancy termination and processed for immunostaining, in situ hybridization, and real-time RT-PCR expression analyses. Islet-like structures appear from approximately week 12 and, unlike the mixed architecture observed in adult islets, fetal islets are initially formed predominantly by aggregated insulin- or glucagon-expressing cells. The period studied (7–22 weeks) coincides with a decrease in the proliferation and an increase in the differentiation of the progenitor cells, the initiation of NGN3 expression, and the appearance of differentiated endocrine cells. The present study provides a detailed characterization of islet formation and expression profiles of key intrinsic and extrinsic factors during human pancreas development. This information is beneficial for the development of efficient protocols that will allow guided in vitro differentiation of hES cells into insulin-producing cells.

scholarly journals Genome wide natural variation of H3K27me3 selectively marks genes predicted to be important for cell differentiation in Phaeodactylum tricornutum

2019 ◽  
Author(s):  
Xue Zhao ◽  
Achal Rastogi ◽  
Anne Flore Deton Cabanillas ◽  
Ouardia Ait Mohamed ◽  
Catherine Cantrel ◽  
...  
Keyword(s):  
Cell Differentiation ◽  
Phaeodactylum Tricornutum ◽  
Natural Variation ◽  
List Type ◽  
Developmentally Regulated ◽  
Unicellular Eukaryotes ◽  
Genome Wide ◽  
Ancestral Function ◽  
Evolutionary Context ◽  
Multicellular Organisms

SummaryIn multicellular organisms, Polycomb Repressive Complex2 (PRC2) is known to deposit H3K27me3 to establish and maintain gene silencing, critical for developmentally regulated processes. PRC2 complex is absent in both widely studied model yeasts which initially suggested that PRC2 arose with the emergence of multicellularity. However, its discovery in several unicellular species including microalgae questions its role in unicellular eukaryotes.Here, we use Phaeodactylum tricornutum enhancer of zeste E(z) knockouts and show that P. tricornutum E(z) is responsible for di and tri-methylation of lysine 27 of histone H3.H3K27me3 depletion abolishes cell morphology in P. tricornutum providing evidence for its role in cell differentiation. Genome wide profiling of H3K27me3 in fusiform and triradiate cells further revealed genes that may specify cell identity.These results suggest a role for PRC2 and its associated mark in cell differentiation in unicellular species and highlight their ancestral function in a broader evolutionary context than is currently appreciated.

scholarly journals RIP140 Represses Intestinal Paneth Cell Differentiation and Interplays with SOX9 Signaling in Colorectal Cancer

Cancers ◽  
2021 ◽  
Vol 13 (13) ◽  
pp. 3192
Author(s):  
Antoine Gleizes ◽  
Mouna Triki ◽  
Sandrine Bonnet ◽  
Naomi Baccari ◽  
Gabriel Jimenez-Dominguez ◽  
...  
Keyword(s):  
Colorectal Cancer ◽  
Cell Differentiation ◽  
Paneth Cell ◽  
Wnt Signaling Pathway ◽  
Cell Lineage ◽  
Human Colon ◽  
Luciferase Reporter ◽  
Loss Of Function ◽  
Sox9 Expression ◽  
Human Colon Cancer

RIP140 is a major transcriptional coregulator of gut homeostasis and tumorigenesis through the regulation of Wnt/APC signaling. Here, we investigated the effect of RIP140 on Paneth cell differentiation and its interplay with the transcription factor SOX9. Using loss of function mouse models, human colon cancer cells, and tumor microarray data sets we evaluated the role of RIP140 in SOX9 expression and activity using RT-qPCR, immunohistochemistry, luciferase reporter assays, and GST-pull down. We first evidence that RIP140 strongly represses the Paneth cell lineage in the intestinal epithelium cells by inhibiting Sox9 expression. We then demonstrate that RIP140 interacts with SOX9 and inhibits its transcriptional activity. Our results reveal that the Wnt signaling pathway exerts an opposite regulation on SOX9 and RIP140. Finally, the levels of expression of RIP140 and SOX9 exhibit a reverse response and prognosis value in human colorectal cancer biopsies. This work highlights an intimate transcriptional cross-talk between RIP140 and SOX9 in intestinal physiopathology.

Hes1 is a negative regulator of inner ear hair cell differentiation

Development ◽  
2000 ◽  
Vol 127 (21) ◽  
pp. 4551-4560 ◽  
Author(s):  
J.L. Zheng ◽  
J. Shou ◽  
F. Guillemot ◽  
R. Kageyama ◽  
W.Q. Gao
Keyword(s):  
Cell Differentiation ◽  
Hair Cell ◽  
Inner Ear ◽  
Cell Fate ◽  
Hair Cells ◽  
Outer Hair Cells ◽  
Negative Regulator ◽  
Pcr Analysis ◽  
Loss Of Function ◽  
Hair Cell Differentiation

Hair cell fate determination in the inner ear has been shown to be controlled by specific genes. Recent loss-of-function and gain-of-function experiments have demonstrated that Math1, a mouse homolog of the Drosophila gene atonal, is essential for the production of hair cells. To identify genes that may interact with Math1 and inhibit hair cell differentiation, we have focused on Hes1, a mammalian hairy and enhancer of split homolog, which is a negative regulator of neurogenesis. We report here that targeted deletion of Hes1 leads to formation of supernumerary hair cells in the cochlea and utricle of the inner ear. RT-PCR analysis shows that Hes1 is expressed in inner ear during hair cell differentiation and its expression is maintained in adulthood. In situ hybridization with late embryonic inner ear tissue reveals that Hes1 is expressed in supporting cells, but not hair cells, of the vestibular sensory epithelium. In the cochlea, Hes1 is selectively expressed in the greater epithelial ridge and lesser epithelial ridge regions which are adjacent to inner and outer hair cells. Co-transfection experiments in postnatal rat explant cultures show that overexpression of Hes1 prevents hair cell differentiation induced by Math1. Therefore Hes1 can negatively regulate hair cell differentiation by antagonizing Math1. These results suggest that a balance between Math1 and negative regulators such as Hes1 is crucial for the production of an appropriate number of inner ear hair cells.

scholarly journals Intrauterine death following intraamniotic triiodothyronine and thyroxine therapy for fetal goitrous hypothyroidism associated with polyhydramnios and caused by a thyroglobulin mutation

2017 ◽  
Vol 2017 ◽  
Author(s):  
Pradeep Vasudevan ◽  
Corrina Powell ◽  
Adeline K Nicholas ◽  
Ian Scudamore ◽  
James Greening ◽  
...  
Keyword(s):  
Prenatal Diagnosis ◽  
Hormone Replacement ◽  
Favourable Outcome ◽  
Compound Heterozygous ◽  
Intrauterine Death ◽  
List Type ◽  
Loss Of Function ◽  
Respiratory Compromise ◽  
Mechanical Complications ◽  
Elective Delivery

Summary In the absence of maternal thyroid disease or iodine deficiency, fetal goitre is rare and usually attributable to dyshormonogenesis, for which genetic ascertainment is not always undertaken in the UK. Mechanical complications include tracheal and oesophageal compression with resultant polyhydramnios, malpresentation at delivery and neonatal respiratory distress. We report an Indian kindred in which the proband (first-born son) had congenital hypothyroidism (CH) without obvious neonatal goitre. His mother’s second pregnancy was complicated by fetal hypothyroid goitre and polyhydramnios, prompting amniotic fluid drainage and intraamniotic therapy (with liothyronine, T3 and levothyroxine, T4). Sadly, intrauterine death occurred at 31 weeks. Genetic studies in the proband demonstrated compound heterozygous novel (c.5178delT, p.A1727Hfs*26) and previously described (c.7123G > A, p.G2375R) thyroglobulin (TG) mutations which are the likely cause of fetal goitre in the deceased sibling. TG mutations rarely cause fetal goitre, and management remains controversial due to the potential complications of intrauterine therapy however an amelioration in goitre size may be achieved with intraamniotic T4, and intraamniotic T3/T4 combination has achieved a favourable outcome in one case. A conservative approach, with surveillance, elective delivery and commencement of levothyroxine neonatally may also be justified, although intubation may be required post delivery for respiratory obstruction. Our observations highlight the lethality which may be associated with fetal goitre. Additionally, although this complication may recur in successive pregnancies, our case highlights the possibility of discordance for fetal goitre in siblings harbouring the same dyshormonogenesis-associated genetic mutations. Genetic ascertainment may facilitate prenatal diagnosis and assist management in familial cases. Learning points: CH due to biallelic, loss-of-function TG mutations is well-described and readily treatable in childhood however mechanical complications from associated fetal goitre may include polyhydramnios, neonatal respiratory compromise and neck hyperextension with dystocia complicating delivery. CH due to TG mutations may manifest with variable phenotypes, even within the same kindred. Treatment options for hypothyroid dyshormogenic fetal goitre in a euthyroid mother include intraamniotic thyroid hormone replacement in cases with polyhydramnios or significant tracheal obstruction. Alternatively, cases may be managed conservatively with radiological surveillance, elective delivery and neonatal levothyroxine treatment, although intubation and ventilation may be required to support neonatal respiratory compromise. Genetic ascertainment in such kindreds may enable prenatal diagnosis and anticipatory planning for antenatal management of further affected offspring.

scholarly journals A novel CASR variant in a family with familial hypocalciuric hypercalcaemia and primary hyperparathyroidism

2020 ◽  
Vol 2020 ◽  
Author(s):  
Satyanarayana V Sagi ◽  
Hareesh Joshi ◽  
Jamie Trotman ◽  
Terence Elsey ◽  
Ashwini Swamy ◽  
...  
Keyword(s):  
Parathyroid Hormone ◽  
Primary Hyperparathyroidism ◽  
Organ Damage ◽  
Urinary Calcium ◽  
Interesting Case ◽  
List Type ◽  
Loss Of Function ◽  
Clearance Ratio ◽  
Hormone Levels ◽  
Severe Hypercalcaemia

Summary Familial hypocalciuric hypercalcaemia (FHH) is a dominantly inherited, lifelong benign disorder characterised by asymptomatic hypercalcaemia, relative hypocalciuria and variable parathyroid hormone levels. It is caused by loss-of-function pathogenic variants in the calcium-sensing receptor (CASR) gene. Primary hyperparathyroidism (PHPT) is characterised by variable hypercalcaemia in the context of non-suppressed parathyroid hormone levels. Unlike patients with FHH, patients with severe hypercalcaemia due to PHPT are usually symptomatic and are at risk of end-organ damage affecting the kidneys, bone, heart, gastrointestinal system and CNS. Surgical resection of the offending parathyroid gland(s) is the treatment of choice for PHPT, while dietary adjustment and reassurance is the mainstay of management for patients with FHH. The occurrence of both FHH and primary hyperparathyroidism (PHPT) in the same patient has been described. We report an interesting case of FHH due to a novel CASR variant confirmed in a mother and her two daughters and the possible coexistence of FHH and PHPT in the mother, highlighting the challenges involved in diagnosis and management. Learning points: Familial hypocalciuric hypercalcaemia (FHH) and primary hyperparathyroidism (PHPT) can coexist in the same patient. Urinary calcium creatinine clearance ratio can play a role in distinguishing between PHPT and FHH. Genetic testing should be considered in managing patients with PHPT and FHH where the benefit may extend to the wider family. Family segregation studies can play an important role in the reclassification of variants of uncertain significance. Parathyroidectomy has no benefit in patients with FHH and therefore, it is important to exclude FHH prior to considering surgery. For patients with coexisting FHH and PHPT, parathyroidectomy will reduce the risk of complications from the severe hypercalcaemia associated with PHPT.

scholarly journals Dravet variant SCN1AA1783V impairs interneuron firing predominantly by altered channel activation

2021 ◽  
Author(s):  
N. Layer ◽  
L. Sonnenberg ◽  
E. Pardo González ◽  
J. Benda ◽  
H. Lerche ◽  
...  
Keyword(s):  
Voltage Dependence ◽  
Dravet Syndrome ◽  
Slice Culture ◽  
List Type ◽  
Slow Inactivation ◽  
Loss Of Function ◽  
Peak Current Density ◽  
Action Potential Firing ◽  
Channel Activation

AbstractDravet syndrome (DS) is a developmental epileptic encephalopathy mainly caused by functional NaV1.1 haploinsufficiency in interneurons (IN). Recently, a new conditional mouse model expressing the recurrent human p.A1783V missense variant has become available. Here we provide an electrophysiological characterization of this variant in tsA201 cells, revealing both altered voltage-dependence of activation and slow inactivation without reduced sodium peak current density. Simulating IN excitability in a Hodgkin-Huxley one-compartment model suggested surprisingly similar firing deficits for Scn1aA1783V and full haploinsufficiency as caused by heterozygous truncation variants. Impaired NaVA1783V channel activation was predicted to have a significantly larger impact on channel function than altered slow inactivation and is therefore proposed as the main mechanism underlying IN dysfunction. The computational model was validated in cortical organotypic slice cultures derived from conditional Scn1aA1783V mice. Pan-neuronal activation of the p.A1783V variant in vitro confirmed the predicted IN firing deficit while demonstrating normal excitability of pyramidal neurons. Taken together these data demonstrate that despite maintained physiological peak currents density LOF gating properties may match effects of full haploinsufficiency on neuronal level, thereby causing DS.HighlightsNaV1.1A1783V alters voltage-dependence of activation and slow inactivation while not affecting fast inactivation.Depolarizing and hyperpolarizing shifts of activation and slow inactivation curves result in combined channel loss of function (LOF).Simulations of NaV1.1A1783V interneuronal properties indicate reduced action potential firing rates comparable to full SCN1A haploinsufficiency, which is often found in Dravet syndrome.In silico modelling identifies impaired channel activation as the predominant mechanism of channel LOF.Panneuronal induction of Scn1a+/A1783V in a cortical slice culture model confirms restriction of loss of function and its restriction to interneurons.

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