scholarly journals REST is a major negative regulator of endocrine differentiation during pancreas organogenesis

2021 ◽  
Author(s):  
Meritxell Rovira ◽  
Goutham Atla ◽  
Miguel Angel Maestro ◽  
Vane Grau ◽  
Javier García-Hurtado ◽  
...  
Keyword(s):  
Endocrine Cells ◽  
Negative Regulator ◽  
Β Cell ◽  
Knock Out ◽  
Endocrine Differentiation ◽  
Conditional Allele ◽  
Embryonic Pancreas ◽  
Pancreatic Endocrine Cells ◽  
Knock Out Mice

SUMMARYUnderstanding genomic regulatory mechanisms of pancreas differentiation is relevant to the pathophysiology of diabetes mellitus, and to the development of replacement therapies. Numerous transcription factors promote β cell differentiation, although less is known about negative regulators. Earlier epigenomic studies suggested that the transcriptional repressor REST could be a suppressor of endocrine gene programs in the embryonic pancreas. However, pancreaticRestknock-out mice failed to show increased numbers of endocrine cells, suggesting that REST is not a major regulator of endocrine differentiation. Using a different conditional allele that enables profound REST inactivation, we now observe a marked increase in the formation of pancreatic endocrine cells. REST inhibition also promoted endocrinogenesis in zebrafish and mouse early postnatal ducts, and induced β-cell specific genes in human adult duct-derived organoids. Finally, we define REST genomic programs that suppress pancreatic endocrine differentiation. These results establish a crucial role of REST as a negative regulator of pancreatic endocrine differentiation.

scholarly journals REST is a major negative regulator of endocrine differentiation during pancreas organogenesis

2021 ◽  
Author(s):  
Meritxell Rovira ◽  
Goutham Atla ◽  
Miguel Angel Maestro ◽  
Vane Grau ◽  
Javier García-Hurtado ◽  
...  
Keyword(s):  
Endocrine Cells ◽  
Cell Formation ◽  
Negative Regulator ◽  
Pancreatic Β Cell ◽  
Β Cell ◽  
Endocrine Differentiation ◽  
Pancreatic Progenitors ◽  
Conditional Allele ◽  
Embryonic Pancreas ◽  
Dependent Inhibition

Multiple transcription factors have been shown to promote pancreatic β-cell differentiation, yet much less is known about negative regulators. Earlier epigenomic studies suggested that the transcriptional repressor REST could be a suppressor of endocrinogenesis in the embryonic pancreas. However, pancreatic Rest knockout mice failed to show abnormal numbers of endocrine cells, suggesting that REST is not a major regulator of endocrine differentiation. Using a different conditional allele that enables profound REST inactivation, we observed a marked increase in pancreatic endocrine cell formation. REST inhibition also promoted endocrinogenesis in zebrafish and mouse early postnatal ducts and induced β-cell-specific genes in human adult duct-derived organoids. We also defined genomic sites that are bound and repressed by REST in the embryonic pancreas. Our findings show that REST-dependent inhibition ensures a balanced production of endocrine cells from embryonic pancreatic progenitors.

scholarly journals Loss of microglial SIRPα promotes synaptic pruning in preclinical models of neurodegeneration

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Xin Ding ◽  
Jin Wang ◽  
Miaoxin Huang ◽  
Zhangpeng Chen ◽  
Jing Liu ◽  
...  
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Knock Out ◽  
Classical Complement Pathway ◽  
Synaptic Remodeling ◽  
The Central Nervous System ◽  
System Activation ◽  
Knock Out Mice ◽  
Synaptic Pruning

AbstractMicroglia play a key role in regulating synaptic remodeling in the central nervous system. Activation of classical complement pathway promotes microglia-mediated synaptic pruning during development and disease. CD47 protects synapses from excessive pruning during development, implicating microglial SIRPα, a CD47 receptor, in synaptic remodeling. However, the role of microglial SIRPα in synaptic pruning in disease remains unclear. Here, using conditional knock-out mice, we show that microglia-specific deletion of SIRPα results in decreased synaptic density. In human tissue, we observe that microglial SIRPα expression declines alongside the progression of Alzheimer’s disease. To investigate the role of SIRPα in neurodegeneration, we modulate the expression of microglial SIRPα in mouse models of Alzheimer’s disease. Loss of microglial SIRPα results in increased synaptic loss mediated by microglia engulfment and enhanced cognitive impairment. Together, these results suggest that microglial SIRPα regulates synaptic pruning in neurodegeneration.

scholarly journals Regulation of Insulin Secretion and β-Cell Mass by Activating Signal Cointegrator 2

2006 ◽  
Vol 26 (12) ◽  
pp. 4553-4563 ◽  
Author(s):  
Seon-Yong Yeom ◽  
Geun Hyang Kim ◽  
Chan Hee Kim ◽  
Heun Don Jung ◽  
So-Yeon Kim ◽  
...  
Keyword(s):  
Insulin Secretion ◽  
Endocrine Cells ◽  
Potential Role ◽  
Cell Mass ◽  
Dominant Negative ◽  
Transcriptional Coactivator ◽  
Β Cells ◽  
Β Cell ◽  
Islet Mass

ABSTRACT Activating signal cointegrator 2 (ASC-2) is a transcriptional coactivator of many nuclear receptors (NRs) and other transcription factors and contains two NR-interacting LXXLL motifs (NR boxes). In the pancreas, ASC-2 is expressed only in the endocrine cells of the islets of Langerhans, but not in the exocrine cells. Thus, we examined the potential role of ASC-2 in insulin secretion from pancreatic β-cells. Overexpressed ASC-2 increased glucose-elicited insulin secretion, whereas insulin secretion was decreased in islets from ASC-2+/− mice. DN1 and DN2 are two dominant-negative fragments of ASC-2 that contain NR boxes 1 and 2, respectively, and block the interactions of cognate NRs with the endogenous ASC-2. Primary rat islets ectopically expressing DN1 or DN2 exhibited decreased insulin secretion. Furthermore, relative to the wild type, ASC-2+/− mice showed reduced islet mass and number, which correlated with increased apoptosis and decreased proliferation of ASC-2+/− islets. These results suggest that ASC-2 regulates insulin secretion and β-cell survival and that the regulatory role of ASC-2 in insulin secretion appears to involve, at least in part, its interaction with NRs via its two NR boxes.

scholarly journals Anatomical, Physiological, and Pharmacological Characteristics of Histidine Decarboxylase Knock-Out Mice: Evidence for the Role of Brain Histamine in Behavioral and Sleep–Wake Control

2002 ◽  
Vol 22 (17) ◽  
pp. 7695-7711 ◽  
Author(s):  
Régis Parmentier ◽  
Hiroshi Ohtsu ◽  
Zahia Djebbara-Hannas ◽  
Jean-Louis Valatx ◽  
Takehiko Watanabe ◽  
...  
Keyword(s):  
Histidine Decarboxylase ◽  
Brain Histamine ◽  
Knock Out ◽  
Knock Out Mice

scholarly journals Wnt9a deficiency discloses a repressive role of Tcf7l2 on endocrine differentiation in the embryonic pancreas

2016 ◽  
Vol 6 (1) ◽  
Author(s):  
G. Pujadas ◽  
S. Cervantes ◽  
A. Tutusaus ◽  
M. Ejarque ◽  
L. Sanchez ◽  
...  
Keyword(s):  
Endocrine Differentiation ◽  
Embryonic Pancreas

Involvement of E-selectin in recruitment of endothelial progenitor cells and angiogenesis in ischemic muscle

Blood ◽  
2007 ◽  
Vol 110 (12) ◽  
pp. 3891-3899 ◽  
Author(s):  
Il-Young Oh ◽  
Chang-Hwan Yoon ◽  
Jin Hur ◽  
Ji-Hyun Kim ◽  
Tae-Youn Kim ◽  
...  
Keyword(s):  
Local Treatment ◽  
Mouse Bone Marrow ◽  
Endothelial Progenitor ◽  
Blocking Antibody ◽  
Knock Out ◽  
Ischemic Limb ◽  
Injection Mechanism ◽  
Knock Out Mice ◽  
Interfering Rna

Abstract E-selectin plays critical roles in tethering leukocytes to endothelial cells (ECs). We studied the role of E-selectin in endothelial progenitor cell (EPC) homing and vasculogenesis. After ischemia, the expression of E-selectin on ECs peaked 6 to 12 hours and returned to baseline at 24 hours, whereas the level of soluble E-selectin (sE-selectin) in serum increased over 24 hours and remained high at day 7. Mouse bone marrow–derived EPCs expressed not only E-selectin but also its ligand. Homing of circulating EPCs to ischemic limb was significantly impaired in E-selectin knock-out mice, as well as wild-type mice pretreated with blocking antibody against E-selectin, which was rescued by local sE-selectin injection. Mechanism for this is that sE-selectin stimulated not only ECs to express ICAM-1, but also EPCs to secrete interleukin-8 (IL-8), leading to enhanced migration and incorporation to ECs capillary formation. In therapeutic aspect, local treatment with sE-selectin enhanced efficacy of EPC transplantation for vasculogenesis and salvage of ischemic limb. Conversely, when E-selectin was knocked down by E-selectin small interfering RNA, blood flow recovery after EPC transplantation was significantly impaired. But this impaired vasculogenesis was rescued by sE-selectin. In conclusion, these data demonstrate E-selectin is a pivotal molecule for EPCs' homing to ischemic limb and vasculogenesis.

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