scholarly journals NaV1.2 haploinsufficiency in Scn2a knock-out mice causes an autistic-like phenotype attenuated with age

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Isabelle Léna ◽  
Massimo Mantegazza
Keyword(s):  
Wide Spectrum ◽  
Autism Spectrum ◽  
Face Validity ◽  
Loss Of Function ◽  
Gene Encoding ◽  
Knock Out ◽  
Adult Mice ◽  
Ohtahara Syndrome ◽  
Knock Out Mice ◽  
Adolescent Period

Abstract Mutations of the SCN2A gene, encoding the voltage gated sodium channel NaV1.2, have been associated to a wide spectrum of epileptic disorders ranging from benign familial neonatal-infantile seizures to early onset epileptic encephalopathies such as Ohtahara syndrome. These phenotypes may be caused by either gain-of-function or loss-of-function mutations. More recently, loss-of-function SCN2A mutations have also been identified in patients with autism spectrum disorder (ASD) without overt epileptic phenotypes. Heterozygous Scn2a knock-out mice (Scn2a+/−) may be a model of this phenotype. Because ASD develops in childhood, we performed a detailed behavioral characterization of Scn2a+/− mice comparing the juvenile/adolescent period of development and adulthood. We used tasks relevant to ASD and the different comorbidities frequently found in this disorder, such as anxiety or intellectual disability. Our data demonstrate that young Scn2a+/− mice display autistic-like phenotype associated to impaired memory and reduced reactivity to stressful stimuli. Interestingly, these dysfunctions are attenuated with age since adult mice show only communicative deficits. Considering the clinical data available on patients with loss-of-function SCN2A mutations, our results indicate that Scn2a+/− mice constitute an ASD model with construct and face validity during the juvenile/adolescent period of development. However, more information about the clinical features of adult carriers of SCN2A mutations is needed to evaluate comparatively the phenotype of adult Scn2a+/− mice.

Dysregulation of DNA methylation during development as a potential mechanisms contributing to obsessive compulsive disorders and autism

2019 ◽  
Author(s):  
German I. Todorov ◽  
Karthikeyan Mayilvahanan ◽  
David Ashurov ◽  
Catarina Cunha
Keyword(s):  
Mouse Model ◽  
Autism Spectrum ◽  
Obsessive Compulsive ◽  
Cancer Treatments ◽  
Knock Out ◽  
Treatment Priority ◽  
Underlying Mechanisms ◽  
Knock Out Mice ◽  
Obsessive Compulsive Disorders ◽  
Compulsive Disorders

Autism Spectrum Disorder (ASD) is a pervasive developmental disorder, that is raising at a concerning rate. However, underlying mechanisms are still to be discovered. Obsessions and compulsions are the most debilitating aspect of these disorders (OCD), and they are the treatment priority for patients. SAPAP3 knock out mice present a reliable mouse model for repetitive compulsive behavior and are mechanistically closely related to the ASD mouse model Shank3 on a molecular level and AMPA receptor net effect. The phenotype of SAPAP3 knock out mice is obsessive grooming that leads to self-inflicted lesions by 4 months of age. Recent studies have accumulated evidence, that epigenetic mechanisms are important effectors in psychiatric conditions such as ASD and OCD. Methylation is the most studied mechanism, that recently lead to drug developments for more precise cancer treatments. We injected SAPAP3 mice with an epigenetic demethylation drug RG108 during pregnancy and delayed the onset of the phenotype in the offspring by 4 months. This result gives us clues about possible mechanism involved in OCD and ASD. Additionally, it shows that modulation of methylation mechanisms during development might be explored as a preventative treatment in the cases of high inherited risk of certain mental health conditions.

scholarly journals Lack of WWC2 Protein Leads to Aberrant Angiogenesis in Postnatal Mice

2021 ◽  
Vol 22 (10) ◽  
pp. 5321
Author(s):  
Viktoria Constanze Brücher ◽  
Charlotte Egbring ◽  
Tanja Plagemann ◽  
Pavel I. Nedvetsky ◽  
Verena Höffken ◽  
...  
Keyword(s):  
Signalling Pathway ◽  
Control Group ◽  
Knock Out ◽  
Ocular Angiogenesis ◽  
Sprouting Angiogenesis ◽  
Adult Mice ◽  
Upstream Regulator ◽  
Knock Out Mice ◽  
Hippo Signalling

The WWC protein family is an upstream regulator of the Hippo signalling pathway that is involved in many cellular processes. We examined the effect of an endothelium-specific WWC1 and/or WWC2 knock-out on ocular angiogenesis. Knock-outs were induced in C57BL/6 mice at the age of one day (P1) and evaluated at P6 (postnatal mice) or induced at the age of five weeks and evaluated at three months of age (adult mice). We analysed morphology of retinal vasculature in retinal flat mounts. In addition, in vivo imaging and functional testing by electroretinography were performed in adult mice. Adult WWC1/2 double knock-out mice differed neither functionally nor morphologically from the control group. In contrast, the retinas of the postnatal WWC knock-out mice showed a hyperproliferative phenotype with significantly enlarged areas of sprouting angiogenesis and a higher number of tip cells. The branching and end points in the peripheral plexus were significantly increased compared to the control group. The deletion of the WWC2 gene was decisive for these effects; while knocking out WWC1 showed no significant differences. The results hint strongly that WWC2 is an essential regulator of ocular angiogenesis in mice. As an activator of the Hippo signalling pathway, it prevents excessive proliferation during physiological angiogenesis. In adult animals, WWC proteins do not seem to be important for the maintenance of the mature vascular plexus.

scholarly journals IFT-A deficiency in juvenile mice impairs biliary development and exacerbates ADPKD liver disease

2020 ◽  
Author(s):  
Wei Wang ◽  
Tana S Pottorf ◽  
Henry H Wang ◽  
Ruochen Dong ◽  
Matthew A. Kavanaugh ◽  
...  
Keyword(s):  
Liver Disease ◽  
Notch Signaling ◽  
Primary Cilia ◽  
Intraflagellar Transport ◽  
Erk Signaling ◽  
Knock Out ◽  
Adult Mice ◽  
Autosomal Dominant Polycystic Kidney ◽  
Knock Out Mice ◽  
Cyst Lining

AbstractPolycystic liver disease (PLD) is characterized by the growth of numerous biliary cysts and presents in patients with Autosomal Dominant Polycystic Kidney Disease (ADPKD), causing significant morbidity. Interestingly, deletion of intraflagellar transport-B (IFT-B) genes in adult mouse models of ADPKD attenuates severity of PKD and PLD. Here we examine the role of deletion of IFT-A gene, Thm1, in PLD of juvenile and adult Pkd2 conditional knock-out mice. Perinatal deletion of Thm1 results in disorganized and expanded biliary regions, biliary fibrosis, shortened primary cilia on CK19+ biliary epithelial cells, and reduced Notch signaling. In contrast, perinatal deletion of Pkd2 causes PLD, with multiple CK19+ biliary epithelial cell-lined cysts, fibrosis, lengthened primary cilia, and increased Notch and ERK signaling. Perinatal deletion of Thm1 in Pkd2 conditional knock-out mice increased hepatomegaly and liver necrosis, indicating enhanced liver disease severity. In contrast to effects in the developing liver, deletion of Thm1 in adult mice, alone and together with Pkd2, did not cause a biliary phenotype nor affect Pkd2-mutant PLD, respectively. However, similar to juvenile PLD, Notch and ERK signaling were increased in adult Pkd2-mutant cyst-lining cholangiocytes. Taken together, Thm1 is required for biliary tract development, likely by enabling Notch signaling, and proper biliary development restricts PLD severity. Unlike IFT-B genes, Thm1 does not affect hepatic cystogenesis, suggesting divergent regulation of signaling and cystogenic processes in the liver by IFT-B and –A. Notably, increased Notch signaling in cyst-lining cholangiocytes may indicate that aberrant activation of this pathway promotes hepatic cystogenesis, presenting as a novel potential therapeutic target.

The role of EP2 receptors in mediating the ultra-long-lasting intraocular pressure reduction by JV-GL1

2020 ◽  
pp. bjophthalmol-2020-317762
Author(s):  
Jacques A Bertrand ◽  
David F Woodward ◽  
Joseph M Sherwood ◽  
Jenny W Wang ◽  
Darryl R Overby
Keyword(s):  
Intraocular Pressure ◽  
Ex Vivo ◽  
Hypotensive Activity ◽  
Long Term Effects ◽  
Gene Encoding ◽  
Knock Out ◽  
Pharmacological Mechanism ◽  
Knock Out Mice

BackgroundA single application of JV-GL1 substantially lowers non-human primate intraocular pressure (IOP) for about a week, independent of dose. This highly protracted effect does not correlate with its ocular biodisposition or correlate with the once-daily dosing regimen for other prostanoid EP2 receptor agonists such as trapenepag or omidenepag. The underlying pharmacological mechanism for the multiday extended activity of JV-GL1 is highly intriguing. The present studies were intended to determine EP2 receptor involvement in mediating the long-term ocular hypotensive activity of JV-GL1 by using mice genetically deficient in EP2 receptors.MethodsThe protracted IOP reduction produced by JV-GL1 was investigated in C57BL/6J and EP2 receptor knock-out mice (B6.129-Ptger2tm1Brey/J; EP2KO). Both ocular normotensive and steroid-induced ocular hypertensive (SI-OHT) mice were studied. IOP was measured tonometrically under general anaesthesia. Aqueous humour outflow facility was measured ex vivo using iPerfusion in normotensive C57BL/6J mouse eyes perfused with 100 nM de-esterified JV-GL1 and in SI-OHT C57BL/6J mouse eyes that had received topical JV-GL1 (0.01%) 3 days prior.ResultsBoth the initial 1-day and the protracted multiday effects of JV-GL1 in the SI-OHT model for glaucoma were abolished by deletion of the gene encoding the EP2 receptor. Thus, JV-GL1 did not lower IOP in SI-OHT EP2KO mice, but in littermate SI-OHT EP2WT control mice, JV-GL1 statistically significantly lowered IOP for 4–6 days.ConclusionsBoth the 1-day and the long-term effects of JV-GL1 on IOP are entirely EP2 receptor dependent.

Placental HTRA1 cleaves alpha-1-antitrypsin to generate a NET-Inhibitory Peptide

Blood ◽  
2021 ◽  
Author(s):  
Robert A. Campbell ◽  
Heather D Campbell ◽  
Joseph Samuel Bircher ◽  
Claudia Valeria de Araujo ◽  
Frederik Denorme ◽  
...  
Keyword(s):  
Serine Protease ◽  
Inhibitory Peptide ◽  
Littermate Control ◽  
Knock Out ◽  
Inhibitory Peptides ◽  
Adult Mice ◽  
Adult Plasma ◽  
Alpha 1 Antitrypsin ◽  
Knock Out Mice ◽  
Mouse Pup

Neutrophil extracellular traps (NETs) are important components of innate immunity. Neonatal neutrophils (PMNs) fail to form NETs due to circulating NET-Inhibitory Peptides (NIPs) -cleavage fragments of alpha-1-antitrypsin (A1AT). However, how fetal and neonatal blood NIPs are generated remains unknown. The placenta expresses High-Temperature Requirement serine protease A1 (HTRA1) during fetal development, which can cleave A1AT. We hypothesized that placentally expressed HTRA1 regulates the formation of NIPs and that NET competency changed in PMNs isolated from neonatal HTRA1-knock out mice (HTRA1-/-). We found that umbilical cord blood plasma has elevated HTRA1 levels compared to adult plasma, and that recombinant and placenta-eluted HTRA1 cleaves A1AT to generate an A1AT cleavage fragment (A1ATM383S-CF) of similar molecular weight to previously identified NIPs that block NET formation by adult neutrophils. We demonstrated that neonatal mouse pup plasma contains A1AT fragments which inhibit NET formation by PMNs isolated from adult mice, indicating that NIP generation during gestation is conserved across species. LPS-stimulated PMNs isolated from HTRA1+/+ littermate control pups exhibit delayed NET formation following birth. However, plasma from HTRA1-/- pups had no detectable NIPs and PMNs from HTRA1-/- pups became NET competent earlier after birth compared to HTRA1+/+ littermate controls. Finally, in the cecal slurry model of neonatal sepsis, A1ATM383S-CF improved survival in C57BL/6 pups by preventing pathogenic NET formation. Our data indicate that placentally expressed HTRA1 is a serine protease that cleaves A1AT in utero to generate NIPs that regulate NET formation by human and mouse PMNs.

scholarly journals Reduced prefrontal synaptic connectivity and disturbed oscillatory population dynamics in the CNTNAP2 model of autism

2018 ◽  
Author(s):  
Maria T. Lazaro ◽  
Jiannis Taxidis ◽  
Tristan Shuman ◽  
Iris Bachmutsky ◽  
Taruna Ikrar ◽  
...  
Keyword(s):  
Laser Scanning ◽  
Phase Locking ◽  
Autism Spectrum ◽  
Repetitive Behaviors ◽  
Neuronal Firing ◽  
Inhibitory Neurons ◽  
Loss Of Function ◽  
Knock Out ◽  
Synaptic Inputs

ABSTRACTLoss of function mutations in CNTNAP2 cause a syndromic form of autism spectrum disorder (ASD) in humans and produce social deficits, repetitive behaviors, and seizures in mice. Yet, the functional effects of these mutations at the cellular and circuit level remain elusive. Using laser scanning photostimulation, whole-cell recordings, and electron microscopy, we found a dramatic decrease in functional excitatory and inhibitory synaptic inputs in L2/3 medial prefrontal cortex (mPFC) of Cntnap2 knock-out (KO) mice. In accordance with decreased synaptic input, KO mice displayed reduced spine and synapse densities, despite normal intrinsic excitability and dendritic complexity. To determine how this decrease in synaptic inputs alters coordination of neuronal firing patterns in vivo, we recorded mPFC local field potentials (LFP) and unit spiking in head-fixed mice during locomotion and rest. In KO mice, LFP power was not significantly altered at all tested frequencies, but inhibitory neurons showed delayed phase-firing and reduced phase-locking to delta and theta oscillations during locomotion. Excitatory neurons showed similar changes but only to delta oscillations. These findings suggest that profound ASD-related alterations in synaptic inputs can yield perturbed temporal coordination of cortical ensembles.

scholarly journals The HSP90/R2TP assembly chaperone promotes cell proliferation in the intestinal epithelium

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Chloé Maurizy ◽  
Claire Abeza ◽  
Bénédicte Lemmers ◽  
Monica Gabola ◽  
Ciro Longobardi ◽  
...  
Keyword(s):  
Rna Polymerase Ii ◽  
Intestinal Epithelium ◽  
Core Component ◽  
Proliferating Cells ◽  
Knock Out ◽  
Differentiated Cells ◽  
Adult Mice ◽  
Cycle Arrest ◽  
Small Intestinal ◽  
Knock Out Mice

AbstractThe R2TP chaperone cooperates with HSP90 to integrate newly synthesized proteins into multi-subunit complexes, yet its role in tissue homeostasis is unknown. Here, we generated conditional, inducible knock-out mice for Rpap3 to inactivate this core component of R2TP in the intestinal epithelium. In adult mice, Rpap3 invalidation caused destruction of the small intestinal epithelium and death within 10 days. Levels of R2TP substrates decreased, with strong effects on mTOR, ATM and ATR. Proliferative stem cells and progenitors deficient for Rpap3 failed to import RNA polymerase II into the nucleus and they induced p53, cell cycle arrest and apoptosis. Post-mitotic, differentiated cells did not display these alterations, suggesting that R2TP clients are preferentially built in actively proliferating cells. In addition, high RPAP3 levels in colorectal tumors from patients correlate with bad prognosis. Here, we show that, in the intestine, the R2TP chaperone plays essential roles in normal and tumoral proliferation.

scholarly journals Nuclear Receptor Corepressors NCoR1 and SMRT Plays Unique Roles in Central Nervous System

2021 ◽  
Vol 5 (Supplement_1) ◽  
pp. A976-A976
Author(s):  
Izuki Amano ◽  
Ayane Ninomiya ◽  
Megan Ritter ◽  
Kristen R Vella ◽  
Anthony Neil Hollenberg ◽  
...  
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
Thyroid Hormone ◽  
Purkinje Cell ◽  
Hormone Receptors ◽  
Thyroid Hormone Receptor ◽  
Autism Spectrum ◽  
Histone Deacetylation ◽  
Knock Out ◽  
Knock Out Mice

Abstract The nuclear corepressor 1 (NCoR1) and the silencing mediator of retinoid and thyroid hormone receptors (SMRT) are critical coregulators of the thyroid hormone receptor (TR), mediating transcriptional repression via histone deacetylation. Thyroid hormone (TH) plays an essential role in many physiological processes via the TR. How the corepressors regulate TR signaling is not fully understood, especially in central nervous system (CNS). To determine the role of NCoR1 and SMRT in the CNS, we used mice with conditional NCoR1 (NCoR1lox/lox) and SMRT (SMRTlox/lox) alleles in combination with mice that express Cre recombinase in a neuronal specific fashion (Snap25-Cre). Global deletion of NCoR1 or SMRT during embryogenesis results in lethality. We also showed that NCoR1/SMRT double knock-out mice die within two weeks after induction of Cre activity in adult mice. Now, we found that neuronal specific NCoR1 or SMRT KO mice survive without obvious impairment of neuronal development. However, NCoR1/SMRT double knock-out mice die within postnatal 1-2 weeks and have impaired body growth. Thus, both NCoR1 and SMRT have important roles in maintaining normal neuronal function. Recently, cased of mutations in NCoR1 and SMRT in humans have been reported. These cases report phenotypes including Autism Spectrum Disorder (ASD) and intellectual disability. The cerebellum has been thought to contribute to motor control and learning. Surprisingly, it has also been shown to be a key brain structure involved in social cognition and its dysfunction may play a role in ASD. The Purkinje cell is the main neuron in the cerebellum. Thus, we generated cerebellar Purkinje cell specific NCoR1/SMRT knock-out mice using L7/Pcp2-Cre mice. In contrast to neuronal specific KO mice, both NCoR1 or SMRT single or double knock-out mice survive until adulthood. SMRT Purkinje cell knock-out mice showed abnormalities in 3ch social interaction test indicating impaired social functioning, similar to some ASD symptoms. Electrophysiological testing showed current injection evoked more action potentials in SMRT KO mice. These results suggest Purkinje cell dysfunction caused by SMRT deletion may result in social disability. Our data demonstrate for the first time that NCoR1 and SMRT have separate functions in different areas of the brain but also have some redundant function when knocked out together in all neurons.

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