scholarly journals MEK inhibition ameliorates social behavior phenotypes in a Spred1 knockout mouse model for RASopathy disorders

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Sarah C. Borrie ◽  
Ellen Plasschaert ◽  
Zsuzsanna Callaerts-Vegh ◽  
Akihiko Yoshimura ◽  
Rudi D’Hooge ◽  
...  

Abstract Background RASopathies are a group of disorders that result from mutations in genes coding for proteins involved in regulating the Ras-MAPK signaling pathway, and have an increased incidence of autism spectrum disorder (ASD). Legius syndrome is a rare RASopathy caused by loss-of-function mutations in the SPRED1 gene. The patient phenotype is similar to, but milder than, Neurofibromatosis type 1—another RASopathy caused by loss-of-function mutations in the NF1 gene. RASopathies exhibit increased activation of Ras-MAPK signaling and commonly manifest with cognitive impairments and ASD. Here, we investigated if a Spred1-/- mouse model for Legius syndrome recapitulates ASD-like symptoms, and whether targeting the Ras-MAPK pathway has therapeutic potential in this RASopathy mouse model. Methods We investigated social and communicative behaviors in Spred1-/- mice and probed therapeutic mechanisms underlying the observed behavioral phenotypes by pharmacological targeting of the Ras-MAPK pathway with the MEK inhibitor PD325901. Results Spred1-/- mice have robust increases in social dominance in the automated tube test and reduced adult ultrasonic vocalizations during social communication. Neonatal ultrasonic vocalization was also altered, with significant differences in spectral properties. Spred1-/- mice also exhibit impaired nesting behavior. Acute MEK inhibitor treatment in adulthood with PD325901 reversed the enhanced social dominance in Spred1-/- mice to normal levels, and improved nesting behavior in adult Spred1-/- mice. Limitations This study used an acute treatment protocol to administer the drug. It is not known what the effects of longer-term treatment would be on behavior. Further studies titrating the lowest dose of this drug that is required to alter Spred1-/- social behavior are still required. Finally, our findings are in a homozygous mouse model, whereas patients carry heterozygous mutations. These factors should be considered before any translational conclusions are drawn. Conclusions These results demonstrate for the first time that social behavior phenotypes in a mouse model for RASopathies (Spred1-/-) can be acutely reversed. This highlights a key role for Ras-MAPK dysregulation in mediating social behavior phenotypes in mouse models for ASD, suggesting that proper regulation of Ras-MAPK signaling is important for social behavior.

Author(s):  
William E. Tidyman ◽  
Alice F. Goodwin ◽  
Yoshiko Maeda ◽  
Ophir D. Klein ◽  
Katherine A. Rauen

Costello syndrome (CS) is a congenital disorder caused by heterozygous activating germline HRAS mutations in the canonical Ras/mitogen-activated protein kinase (Ras/MAPK) pathway. CS is one of the RASopathies, a large group of syndromes due to mutations within various components of the Ras/MAPK pathway. An important part of the phenotype that greatly impacts quality of life is hypotonia. To gain a better understanding of the mechanisms underlying hypotonia in CS, a mouse model with an activating HrasG12V allele was utilized. We identified a skeletal myopathy that was due in part to an inhibition of embryonic myogenesis and myofiber formation, resulting in a reduction of myofiber size and number that led to reduced muscle mass and strength. In addition to hyperactivation of the Ras/MAPK and PI3K/AKT pathways, there was a significant reduction of p38 signaling, as well as global transcriptional alterations consistent with the myopathic phenotype. Inhibition of Ras/MAPK pathway signaling using a MEK inhibitor rescued the HrasG12V myopathy phenotype both in vitro and in vivo, demonstrating that increased MAPK signaling is the main cause of the muscle phenotype in CS.


2021 ◽  
Vol 11 ◽  
Author(s):  
Marie-Maude Geoffray ◽  
Bruno Falissard ◽  
Jonathan Green ◽  
Browyn Kerr ◽  
D. Gareth Evans ◽  
...  

Dysregulation of the Ras MAPK signaling pathway is implicated in the pathogenesis of autism spectrum disorder (ASD). The RASopathies, a group of disorders caused by mutations of the Ras/MAPK pathway genes, share many overlapping clinical features. Studies suggest a high prevalence of ASD in the RASopathies, but detailed characterization of the ASD profile is lacking. The aim of this study was to compare the ASD symptom profile of three distinct RASopathies associated with both gain-of-function and loss-of-function mutations: neurofibromatosis type 1 (NF1), Noonan syndrome (NS), and cardiofaciocutaneous syndrome (CFC). Participants were drawn from existing databases if they had a diagnosis of a RASopathy, met the criteria for ASD, and were able to communicate verbally. We compared the phenotypic profile of NF1 + ASD (n = 48), NS + ASD (n = 11), and CFC + ASD (n = 7) on the Autism Diagnostic Inventory (ADI-R) and the Autism Diagnostic Observation Schedule (ADOS). We found subtle but non-significant group differences with higher levels of social impairments and lower restricted repetitive behaviors in the NF1 group as compared with the NS and CFC groups. We observed group differences in developmental milestones with most severe delays in CFC, followed by NS and NF1. Our results suggest that despite developmental differences, the ASD profile remains relatively consistent across the three RASopathies. Though our results need confirmation in larger samples, they suggest the possibility that treatment and mechanistic insights developed in the context of one RASopathy may be generalizable to others and possibly to non-syndromic ASD associated with dysregulation of Ras/MAPK pathway genes.


2021 ◽  
Vol 14 (1) ◽  
Author(s):  
Kohei Kitagawa ◽  
Kensuke Matsumura ◽  
Masayuki Baba ◽  
Momoka Kondo ◽  
Tomoya Takemoto ◽  
...  

AbstractAutism spectrum disorder (ASD) is a highly prevalent neurodevelopmental disorder characterized by core symptoms of impaired social behavior and communication. Recent studies have suggested that the oxytocin system, which regulates social behavior in mammals, is potentially involved in ASD. Mouse models of ASD provide a useful system for understanding the associations between an impaired oxytocin system and social behavior deficits. However, limited studies have shown the involvement of the oxytocin system in the behavioral phenotypes in mouse models of ASD. We have previously demonstrated that a mouse model that carries the ASD patient-derived de novo mutation in the pogo transposable element derived with zinc finger domain (POGZWT/Q1038R mice), showed ASD-like social behavioral deficits. Here, we have explored whether oxytocin (OXT) administration improves impaired social behavior in POGZWT/Q1038R mice and found that intranasal oxytocin administration effectively restored the impaired social behavior in POGZWT/Q1038R mice. We also found that the expression level of the oxytocin receptor gene (OXTR) was low in POGZWT/Q1038R mice. However, we did not detect significant changes in the number of OXT-expressing neurons between the paraventricular nucleus of POGZWT/Q1038R mice and that of WT mice. A chromatin immunoprecipitation assay revealed that POGZ binds to the promoter region of OXTR and is involved in the transcriptional regulation of OXTR. In summary, our study demonstrate that the pathogenic mutation in the POGZ, a high-confidence ASD gene, impairs the oxytocin system and social behavior in mice, providing insights into the development of oxytocin-based therapeutics for ASD.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Daniela Lichtman ◽  
Eyal Bergmann ◽  
Alexandra Kavushansky ◽  
Nadav Cohen ◽  
Nina S. Levy ◽  
...  

AbstractIQSEC2 is an X-linked gene that is associated with autism spectrum disorder (ASD), intellectual disability, and epilepsy. IQSEC2 is a postsynaptic density protein, localized on excitatory synapses as part of the NMDA receptor complex and is suggested to play a role in AMPA receptor trafficking and mediation of long-term depression. Here, we present brain-wide structural volumetric and functional connectivity characterization in a novel mouse model with a missense mutation in the IQ domain of IQSEC2 (A350V). Using high-resolution structural and functional MRI, we show that animals with the A350V mutation display increased whole-brain volume which was further found to be specific to the cerebral cortex and hippocampus. Moreover, using a data-driven approach we identify putative alterations in structure–function relations of the frontal, auditory, and visual networks in A350V mice. Examination of these alterations revealed an increase in functional connectivity between the anterior cingulate cortex and the dorsomedial striatum. We also show that corticostriatal functional connectivity is correlated with individual variability in social behavior only in A350V mice, as assessed using the three-chamber social preference test. Our results at the systems-level bridge the impact of previously reported changes in AMPA receptor trafficking to network-level disruption and impaired social behavior. Further, the A350V mouse model recapitulates similarly reported brain-wide changes in other ASD mouse models, with substantially different cellular-level pathologies that nonetheless result in similar brain-wide alterations, suggesting that novel therapeutic approaches in ASD that result in systems-level rescue will be relevant to IQSEC2 mutations.


2018 ◽  
Vol 39 (5) ◽  
pp. 676-700 ◽  
Author(s):  
Mylène Tajan ◽  
Romain Paccoud ◽  
Sophie Branka ◽  
Thomas Edouard ◽  
Armelle Yart

Abstract Noonan syndrome [NS; Mendelian Inheritance in Men (MIM) #163950] and related syndromes [Noonan syndrome with multiple lentigines (formerly called LEOPARD syndrome; MIM #151100), Noonan-like syndrome with loose anagen hair (MIM #607721), Costello syndrome (MIM #218040), cardio-facio-cutaneous syndrome (MIM #115150), type I neurofibromatosis (MIM #162200), and Legius syndrome (MIM #611431)] are a group of related genetic disorders associated with distinctive facial features, cardiopathies, growth and skeletal abnormalities, developmental delay/mental retardation, and tumor predisposition. NS was clinically described more than 50 years ago, and disease genes have been identified throughout the last 3 decades, providing a molecular basis to better understand their physiopathology and identify targets for therapeutic strategies. Most of these genes encode proteins belonging to or regulating the so-called RAS/MAPK signaling pathway, so these syndromes have been gathered under the name RASopathies. In this review, we provide a clinical overview of RASopathies and an update on their genetics. We then focus on the functional and pathophysiological effects of RASopathy-causing mutations and discuss therapeutic perspectives and future directions.


2019 ◽  
Author(s):  
Patricia Kabitzke ◽  
Diana Morales ◽  
Dansha He ◽  
Kimberly Cox ◽  
Jane Sutphen ◽  
...  

3.AbstractBackgroundPhenotyping mouse model systems of human disease has proven to be a difficult task, with frequent poor inter- and intra-laboratory replicability and translatability, particularly in behavioral domains such as social and verbal function. However, establishing robust animal model systems with strong construct validity is of fundamental importance as they are central tools for understanding disease pathophysiology and developing therapeutics. To complete our studies of mouse model systems relevant to autism spectrum disorder (ASD), we present a replication of the main findings from our two published studies comprising five genetic mouse model systems of ASD.MethodsTo assess the robustness of our previous results, we chose the two model systems that showed the greatest phenotypic differences, the Shank3/F and Cntnap2, and repeated assessments of general health, activity, and social behavior. We additionally explored all five model systems in the same framework, comparing all results obtained in this three-yearlong effort using informatics techniques to look for commonalities and differences.ResultsResults in the current study were very similar to our previously published results. The informatics signatures of the two model systems chosen for the replication showed that they were most distinguished by activity levels. Although the two model systems were opposite in this regard, those aspects of their social behavior not confounded by activity (vocalizations) were similar.ConclusionsOur results showed high intra-laboratory replicability of results, even for those with effect sizes that were not particularly large, suggesting that discrepancies in the literature may be dependent on subtle differences in testing conditions, housing enrichment, or background strains and not so much on the variability of the behavioral phenotypes. The overall informatics analysis suggests two main classes of model systems that in some aspects lie on opposite ends of the behavioral spectrum, supporting the view that autism is not a unitary concept.


Author(s):  
Ryan Sullivan ◽  
Patricia LoRusso ◽  
Scott Boerner ◽  
Reinhard Dummer

The treatment of melanoma has been revolutionized over the past decade with the development of effective molecular and immune targeted therapies. The great majority of patients with melanoma have mutations in oncogenes that predominantly drive signaling through the mitogen activated protein kinase (MAPK) pathway. Analytic tools have been developed that can effectively stratify patients into molecular subsets based on the identification of mutations in oncogenes and/or tumor suppressor genes that drive the MAPK pathway. At the same time, potent and selective inhibitors of mediators of the MAPK pathway such as RAF, MEK, and ERK have become available. The most dramatic example is the development of single-agent inhibitors of BRAF (vemurafenib, dabrafenib, encorafenib) and MEK (trametinib, cobimetinib, binimetinib) for patients with metastatic BRAFV600-mutant melanoma, a subset that represents 40% to 50% of patients with metastatic melanoma. More recently, the elucidation of mechanisms underlying resistance to single-agent BRAF inhibitor therapy led to a second generation of trials that demonstrated the superiority of BRAF inhibitor/MEK inhibitor combinations (dabrafenib/trametinib; vemurafenib/cobimetinib) compared to single-agent BRAF inhibitors. Moving beyond BRAFV600targeting, a number of other molecular subsets—such as mutations in MEK, NRAS, and non-V600 BRAF and loss of function of the tumor suppressor neurofibromatosis 1 ( NF1)—are predicted to respond to MAPK pathway targeting by single-agent pan-RAF, MEK, or ERK inhibitors. As these strategies are being tested in clinical trials, preclinical and early clinical trial data are now emerging about which combinatorial approaches might be best for these patients.


2004 ◽  
Vol 287 (4) ◽  
pp. E758-E766 ◽  
Author(s):  
Anne W. Harmon ◽  
David S. Paul ◽  
Yashomati M. Patel

In 3T3-L1 adipocytes, insulin activates three major signaling cascades, the phosphoinositide 3-kinase (PI3K) pathway, the Cbl pathway, and the mitogen-activated protein kinase (MAPK) pathway. Although PI3K and Cbl mediate insulin-stimulated glucose uptake by promoting the translocation of the insulin-responsive glucose transporter (GLUT4) to the plasma membrane, the MAPK pathway does not have an established role in insulin-stimulated glucose uptake. We demonstrate in this report that PI3K inhibitors also inhibit the MAPK pathway. To investigate the role of the MAPK pathway separately from that of the PI3K pathway in insulin-stimulated glucose uptake, we used two specific inhibitors of MAPK kinase (MEK) activity, PD-98059 and U-0126, which reduced insulin-stimulated glucose uptake by ∼33 and 50%, respectively. Neither MEK inhibitor affected the activation of Akt or PKCζ/λ, downstream signaling molecules in the PI3K pathway. Inhibition of MEK with U-0126 did not prevent GLUT4 from translocating to the plasma membrane, nor did it inhibit the subsequent docking and fusion of GLUT4- myc with the plasma membrane. MEK inhibitors affected glucose transport mediated by GLUT4 but not GLUT1. Importantly, the presence of MEK inhibitors only at the time of the transport assay markedly impaired both insulin-stimulated glucose uptake and MAPK signaling. Conversely, removal of MEK inhibitors before the transport assay restored glucose uptake and MAPK signaling. Collectively, our studies suggest a possible role for MEK in the activation of GLUT4.


2017 ◽  
Vol 2017 ◽  
pp. 1-13 ◽  
Author(s):  
Jin-lun Lai ◽  
Yu-hui Liu ◽  
Yong-chong Peng ◽  
Pan Ge ◽  
Chen-fei He ◽  
...  

Indirubin is a Chinese medicine extracted from indigo and known to be effective for treating chronic myelogenous leukemia, neoplasia, and inflammatory disease. This study evaluated the in vivo anti-inflammatory activity of indirubin in a lipopolysaccharide- (LPS-) induced mouse mastitis model. The indirubin mechanism and targets were evaluated in vitro in mouse mammary epithelial cells. In the mouse model, indirubin significantly attenuated the severity of inflammatory lesions, edema, inflammatory hyperemia, milk stasis and local tissue necrosis, and neutrophil infiltration. Indirubin significantly decreased myeloperoxidase activity and downregulated the production of tumor necrosis factor-α, interleukin-1β(IL-1β), and IL-6 caused by LPS. In vitro, indirubin inhibited LPS-stimulated expression of proinflammatory cytokines in a dose-dependent manner. It also downregulated LPS-induced toll-like receptor 4 (TLR4) expression and inhibited phosphorylation of LPS-induced nuclear transcription factor-kappa B (NF-κB) P65 protein and inhibitor of kappa B. In addition to its effect on the NF-κB signaling pathway, indirubin suppressed the mitogen-activated protein kinase (MAPK) signaling by inhibiting phosphorylation of extracellular signal-regulated kinase (ERK), P38, and c-jun NH2-terminal kinase (JNK). Indirubin improved LPS-induced mouse mastitis by suppressing TLR4 and downstream NF-κB and MAPK pathway inflammatory signals and might be a potential treatment of mastitis and other inflammatory diseases.


2021 ◽  
Vol 15 ◽  
Author(s):  
Maria Jesus Herrero ◽  
Li Wang ◽  
David Hernandez-Pineda ◽  
Payal Banerjee ◽  
Heidi Y. Matos ◽  
...  

In humans, mutations in the transcription factor encoding gene, FOXP2, are associated with language and Autism Spectrum Disorders (ASD), the latter characterized by deficits in social interactions. However, little is known regarding the function of Foxp2 in male or female social behavior. Our previous studies in mice revealed high expression of Foxp2 within the medial subnucleus of the amygdala (MeA), a limbic brain region highly implicated in innate social behaviors such as mating, aggression, and parental care. Here, using a comprehensive panel of behavioral tests in male and female Foxp2+/– heterozygous mice, we investigated the role Foxp2 plays in MeA-linked innate social behaviors. We reveal significant deficits in olfactory processing, social interaction, mating, aggressive, and parental behaviors. Interestingly, some of these deficits are displayed in a sex-specific manner. To examine the consequences of Foxp2 loss of function specifically in the MeA, we conducted a proteomic analysis of microdissected MeA tissue. This analyses revealed putative sex differences expression of a host of proteins implicated in neuronal communication, connectivity, and dopamine signaling. Consistent with this, we discovered that MeA Foxp2-lineage cells were responsive to dopamine with differences between males and females. Thus, our findings reveal a central and sex-specific role for Foxp2 in social behavior and MeA function.


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