scholarly journals Tsc1 haploinsufficiency leads to Pax2 dysregulation in the developing murine cerebellum

2021 ◽  
Author(s):  
Ines Serra ◽  
Ana Stravs ◽  
Catarina Osorio ◽  
Maria Roa Oyaga ◽  
Martijn Schonewille ◽  
...  
Keyword(s):  
Neurodevelopmental Disorder ◽  
Suppressor Gene ◽  
Inhibitory Interneuron ◽  
Autism Spectrum ◽  
Tumour Suppressor Gene ◽  
Mtor Pathway ◽  
Cerebellar Development ◽  
Mrna Levels ◽  
Gene And Protein Expression ◽  
And Migration

Tuberous sclerosis complex 1 (TSC1) is a tumour suppressor gene that inhibits the mechanistic target of rapamycin (mTOR) pathway. Mutations in TSC1 lead to a rare complex disorder of the same name, in which up to 50% of patients present with autism spectrum disorder (ASD). ASD is a highly prevalent, early-onset neurodevelopmental disorder, characterized by social deficits and repetitive behaviours, although the type and severity of symptoms show wide variability across individuals. Amongst different brain areas proposed to play a role in the development of ASD, the cerebellum is commonly reported to be altered, and cerebellar-specific deletion of Tsc1 in mice is sufficient to induce an ASD-like phenotype. Given that the mTOR pathway is crucial for proper cell replication and migration, this suggests that dysregulation of this pathway, particularly during critical phases of cerebellar development, could contribute to the establishment of ASD. Here, we used a mouse model of TSC to investigate gene and protein expression during embryonic and early postnatal periods of cerebellar development. We found that, at E18 and P7, mRNA levels of the cerebellar inhibitory interneuron marker Pax2 were dysregulated. This was accompanied by changes in the expression of mTOR pathway-related genes and downstream phosphorylation of S6. Differential gene correlation analysis revealed dynamic changes in correlated gene pairs across development, with an overall loss of correlation between mTOR- and cerebellar-related genes in Tsc1 mutants compared to controls. We corroborated the genetic findings by characterizing the mTOR pathway and cerebellar development on protein and cellular levels with Western blot and immunohistochemistry. We found that Pax2-expressing cells were hypertrophic at E18 while, at P7, their number was increased and maturation into parvalbumin-expressing cells delayed. Our findings indicate that E18 and P7 are crucial time points in cerebellar development in mice that are particularly susceptible to mTOR pathway dysregulation.

Abstract 370: MicroRNA-19b Contributes to Cardiac Fibrosis

2015 ◽  
Vol 117 (suppl_1) ◽  
Author(s):  
Ping Chen ◽  
Dongchao Lv ◽  
Jiahong Xu ◽  
Qiulian Zhou ◽  
Qi Sun ◽  
...  
Keyword(s):  
Heart Failure ◽  
Cardiac Fibrosis ◽  
Cardiac Fibroblasts ◽  
Suppressor Gene ◽  
Tissue Growth ◽  
Neonatal Rat ◽  
Cell Counting ◽  
Mrna Levels ◽  
And Migration ◽  
Proliferation And Migration

Fibrosis is one of the most important characteristics of cardiac remodeling during heart failure. The accumulation of extracellular matrix (ECM) within myocardium is the major feature of cardiac fibrosis. microRNA (miR)-19b, a key functional member of miR-19-72 cluster family, has been suggested to be involved in aging-induced heart failure through regulating ECM-related proteins, such as connective tissue growth factor (CTGF), thrombospondin-1 (TSP-1), collagen-1A1, and collagen-3A1. In the current study, we aimed to investigate the role of miR-19b in cardiac fibroblast function and ECM production using neonatal rat cardiac fibroblasts in primary culture. We found that overexpression of miR-19b increased, while inhibition of miR-19b decreased the proliferation and migration of cardiac fibroblasts, using Cell Counting Kit-8 (CCK-8) (0.660±0.019 vs 0.720±0.014 in nc-mimic and miR-19b mimic, 0.506±0.009 vs 0.454±0.008 in nc-inhibitor and miR-19b inhibitor, respectively), EdU incorporation assay (0.059±0.002 vs 0.096±0.006 in nc-mimic and miR-19b mimic, 0.059±0.006 vs 0.040±0.003 in nc-inhibitor and miR-19b inhibitor, respectively), and wound healing assay (0.528±0.024 vs 0.896±0.027 in nc-mimic and miR-19b mimic,0.520±0.028 vs 0.174±0.019 in nc-inhibitor and miR-19b inhibitor, respectively), respectively. Meanwhile, the inhibition of miR-19b downregulated the mRNA levels of α-SMA (0.556±0.048 vs 1.038±0.137 in nc-inhibitor and miR-19b inhibitor, respectively) and collagen-1 (1.023±0.116 vs 0.551±0.033 in nc-inhibitor and miR-19b inhibitor, respectively) in cardiac fibroblasts, indicating a reduction in fibroblast activation and ECM production via miR-19b inhibition. Furthermore, we found that PTEN was negatively regulated by miR-19b in cardiac fibroblasts using western blot analysis. PTEN, a well-known tumor-suppressor gene, has been known to inhibit cell proliferation and migration. However, it remains to be further clarified whether PTEN could mediate the effect of miR-19b in the proliferation, migration and activation of fibroblasts. These data might provide important evidence suggesting that miR-19b could be a potential therapeutic target for cardiac fibrosis.

scholarly journals ITIH5, a p53-responsive gene, inhibits the growth and metastasis of melanoma cells by downregulating the transcriptional activity of KLF4

2021 ◽  
Vol 12 (5) ◽  
Author(s):  
Jia Liu ◽  
Feng Cao ◽  
Xiaojie Li ◽  
Li Zhang ◽  
Zhengrong Liu ◽  
...  
Keyword(s):  
Melanoma Cell ◽  
Transcriptional Activity ◽  
Ex Vivo ◽  
Normal Skin ◽  
Suppressor Gene ◽  
Melanoma Cells ◽  
Tumour Suppressor Gene ◽  
Cell Growth And Migration ◽  
And Migration

AbstractITIH5, a member of the inter-α-trypsin inhibitory (ITI) gene family, acts as a putative tumour-suppressor gene in many cancers. However, its role and the regulatory mechanism in melanoma are still unclear. Here, we found that the expression of ITIH5 was decreased in melanoma tissues compared with normal skin tissues. Decreased expression of ITIH5 was correlated with clinicopathological features and predicted poor prognosis in patients with melanoma. Forced expression of ITIH5 significantly inhibited melanoma cell proliferation and metastasis in vitro and ex vivo while knockdown of ITIH5 expression enhanced the malignant behaviour of melanoma cells. In further mechanistic studies, we showed that p53 can directly bind to the promoter of ITIH5 and thus promotes transcription of ITIH5 in melanoma cells. Additionally, we found that ITIH5 interacted with Krüppel-like factor 4 (KLF4) and inhibited its transcriptional activity. Collectively, our data not only identified a tumour-suppressive role of ITIH5 in melanoma but also revealed that upregulation of ITIH5 by p53 suppressed melanoma cell growth and migration likely by downmodulating the transcriptional activity of KLF4.

scholarly journals The impact of phosphorylated Pten at threonine 366 on cortical connectivity and behaviour

2021 ◽  
Author(s):  
Julia Ledderose ◽  
Jorge A Benitez ◽  
Amanda J Roberts ◽  
Rachel Reed ◽  
Willem Bintig ◽  
...  
Keyword(s):  
Sensory Processing ◽  
Cortical Neurons ◽  
Suppressor Gene ◽  
Autism Spectrum ◽  
Tumour Suppressor Gene ◽  
Repetitive Behaviour ◽  
Cortical Input ◽  
Brain Circuits ◽  
Neuron Size ◽  
The Impact

The lipid phosphatase Pten (phosphatase and tensin homologue on chromosome 10) is a key tumour suppressor gene and an important regulator of neuronal signalling. Pten mutations have been identified in patients with autism spectrum disorders, characterized by macrocephaly, impaired social interactions and communication, repetitive behaviour, intellectual disability, and epilepsy. Pten enzymatic activity is regulated by a cluster of phosphorylation sites at the C-terminus of the protein. Here we specifically focussed on the role of Pten T366 phosphorylation and generated a knock-in mouse line in which Pten T366 was substituted with alanine (PtenT366A/T366A). We identify that phosphorylation of Pten at T366 controls neuron size and connectivity of brain circuits involved in sensory processing. We show in behavioural tests that PtenT366/T366A mice exhibit cognitive deficits and selective sensory impairments, with significant differences in male individuals. We identify restricted cellular overgrowth of cortical neurons in PtenT366A/T366A brains, linked to increases in both dendritic arborization and soma size. In a combinatorial approach of anterograde and retrograde monosynaptic tracing using rabies virus, we characterize differences in connectivity to the primary somatosensory cortex of PtenT366A/T366A brains, with imbalances in long-range cortico-cortical input to neurons. We conclude that phosphorylation of Pten at T366 controls neuron size and connectivity of brain circuits involved in sensory processing and propose that PTEN T366 signalling may account for a subset of autism-related functions of Pten.

scholarly journals DNMT3B Expression Might Contribute to Abnormal Methylation of RASSF1A in Lager Colorectal Adenomatous Polyps

2020 ◽  
Vol 2020 ◽  
pp. 1-16
Author(s):  
Xianmei Meng ◽  
Na Liu ◽  
Yanbin Jia ◽  
Kerui Gong ◽  
Jingjie Zhang ◽  
...  
Keyword(s):  
Promoter Hypermethylation ◽  
Suppressor Gene ◽  
Dna Methyltransferases ◽  
Tumour Suppressor Gene ◽  
Tumour Suppressor ◽  
Adenomatous Polyps ◽  
Mrna Levels ◽  
Global Methylation ◽  
Protein Levels ◽  
Colorectal Mucosa

Background. It is pretty well known that DNA methyltransferases (DNMTs) are actively involved in abnormal cell growth. The goal of the current study is to explore the correlation between DNMT expression and colorectal adenomatous polyps (CAPs). Method. Twenty pairs of CAP samples with a diameter≥10 mm and corresponding normal colorectal mucosa (NCM) tissues from patients were used in the present study. The expression levels and activity of DNA methyltransferases (DNMTs) were measured in the CAP tissues. The global methylation and the promoter methylation level of 3 kinds of tumour suppressor gene were detected. Results. mRNA and protein levels of DNMT3B were found to be elevated in the CAP tissues compared with the control tissue. Additionally, the methylation of long interspersed nuclear elements-1 (LINE-1/L1) was decreased in the CAP tissue. Furthermore, methylation of the promoter of a tumour suppressor gene Ras association domain family 1A (RASSF1A) was increased in the CAP tissues, while the mRNA levels of RASSF1A were decreased. Conclusions. These results suggest that the overexpression of DNMT3B may contribute to a role in the genesis of CAPs through the hypomethylation of chromosomes in the whole cell and promoter hypermethylation of RASSF1A.

The interaction of the second Kunitz-type domain (KD2) of TFPI-2 with a novel interaction partner, prosaposin, mediates the inhibition of the invasion and migration of human fibrosarcoma cells

2011 ◽  
Vol 441 (2) ◽  
pp. 665-674 ◽  
Author(s):  
Chundi Xu ◽  
Fenge Deng ◽  
Zuohua Mao ◽  
Jing Zhang ◽  
Huijun Wang ◽  
...  
Keyword(s):  
Serine Proteinase ◽  
Suppressor Gene ◽  
Tumour Suppressor Gene ◽  
Tumour Suppressor ◽  
Invasion And Migration ◽  
Fibrosarcoma Cells ◽  
Tissue Factor Pathway ◽  
Kunitz Type ◽  
Human Fibrosarcoma Cells ◽  
And Migration

TFPI-2 (tissue factor pathway inhibitor-2) has recently been recognized as a new tumour suppressor gene. Low expression of this protein in several types of cancers allows for enhanced tumour growth, invasion and metastasis. To investigate the molecular mechanism responsible for the tumour-suppressor effects of TFPI-2, we performed yeast two-hybrid analysis and identified PSAP (prosaposin) as a TFPI-2-interacting partner. This interaction was confirmed by co-immunoprecipitation and immunofluorescence. The region of TFPI-2 that interacts with PSAP is located in the KD2 (Kunitz-type domain 2). Further study showed that PSAP does not affect the function of TFPI-2 as a serine proteinase inhibitor, but that TFPI-2 could inhibit the invasion-promoting effects of PSAP in human HT1080 fibrosarcoma cells. The results of the present study revealed that TFPI-2 interacts with PSAP, which may play an important role in the physiology and pathology of diseases such as cancer.

PTEN is essential for cell migration but not for fate determination and tumourigenesis in the cerebellum

Development ◽  
2002 ◽  
Vol 129 (14) ◽  
pp. 3513-3522 ◽  
Author(s):  
Silvia Marino ◽  
Paul Krimpenfort ◽  
Carly Leung ◽  
Hetty A. G. M. van der Korput ◽  
Jan Trapman ◽  
...  
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
System Development ◽  
Cell Cycle Control ◽  
Neoplastic Transformation ◽  
Suppressor Gene ◽  
Tumour Suppressor Gene ◽  
Nervous System Development ◽  
A Cell ◽  
And Migration

PTEN is a tumour suppressor gene involved in cell cycle control, apoptosis and mediation of adhesion and migration signalling. Germline mutations of PTEN in humans are associated with familial tumour syndromes, among them Cowden disease. Glioblastomas, highly malignant glial tumours of the central nervous system frequently show loss of PTEN. Recent reports have outlined some aspects of PTEN function in central nervous system development. Using a conditional gene disruption approach, we inactivated Pten in mice early during embryogenesis locally in a region specific fashion and later during postnatal development in a cell-specific manner, to study the role of PTEN in differentiation, migration and neoplastic transformation. We show that PTEN is required for the realisation of normal cerebellar architecture, for regulation of cell and organ size, and for proper neuronal and glial migration. However, PTEN is not required for cell differentiation and lack of PTEN is not sufficient to induce neoplastic transformation of neuronal or glial cells

An Autism-Related, Nonsense Foxp1 Mutant Induces Autophagy and Delays Radial Migration of the Cortical Neurons

2018 ◽  
Vol 29 (7) ◽  
pp. 3193-3208 ◽  
Author(s):  
Xue Li ◽  
Xin Han ◽  
Xiaomeng Tu ◽  
Dan Zhu ◽  
Yue Feng ◽  
...  
Keyword(s):  
Cortical Neurons ◽  
De Novo ◽  
Neurodevelopmental Disorder ◽  
Neuronal Cells ◽  
Ectopic Expression ◽  
Autism Spectrum ◽  
Dendritic Morphology ◽  
Heterozygous Mutation ◽  
Cortical Cells ◽  
And Migration

Abstract Autism spectrum disorder (ASD) is a complex neurodevelopmental disorder that has a strong genetic component. Disruptions of FOXP1, a transcription factor expressed in the developing cerebral cortex, were associated with ASD. FOXP1(R525X) is a de novo heterozygous mutation found in patients with autism and severe mental retardation. To explore the neuronal basis of FOXP1(R525X) in ASD, we created Foxp1(R521X), a mouse homolog of the human variant. Ectopic expression of Foxp1(R521X) led to cytoplasmic aggregates and activated macroautophagy in neuroblastoma N2a cells and the developing neuronal cells. Cortical neurons expressing Foxp1(R521X) exhibited delayed migration and altered dendritic morphology. As a control, mutant Y435X that was expressed diffusively in the cytoplasm did not induce autophagy and migration delay in the cortex. The embryonic cortical cells had a minimal activity of nonsense-mediated mRNA decay (NMD) as assayed by a splicing-dependent NMD reporter. We hypothesize that the developing neuronal cells use autophagy but not NMD as a safeguard mechanism against nonsense mutant aggregates, resulting in impairment of the cortical development. This study suggests a novel mechanism other than heterozygous loss of FOXP1 for the development of ASD and may advance our understanding of the complex relationships between gene mutation and the related psychiatric disorders.

RBM5 Acts as Tumor Suppressor in Medulloblastoma through Regulating Wnt/β-Catenin Signaling

2020 ◽  
Vol 83 (3) ◽  
pp. 242-250
Author(s):  
Jianzhong Yu ◽  
Guangchun Ji ◽  
Wei Shi ◽  
Rui Zhao ◽  
Wenjun Shen ◽  
...  
Keyword(s):  
Tumor Suppressor ◽  
Expression Patterns ◽  
Suppressor Gene ◽  
Sequencing Analysis ◽  
Mrna Levels ◽  
Breast Cancers ◽  
Kaplan Meier ◽  
Whole Exome ◽  
And Migration

Introduction: RBM5 acts as a tumor suppressor gene in lung and breast cancers; however, its role in the pathogenesis of medulloblastoma (MB) remains unclear. We previously identified 4 RBM5 mutations in whole exome sequencing analysis of 40 MB patients. This study examined the role of RBM5 in MB progression. Methods: The expression patterns of RBM5 in tissues of 40 MB patients were analyzed using immunohistochemistry. Associations between RBM5 expression and overall survival (OS) were evaluated using Kaplan-Meier analysis. The RBM5 role in Daoy cells’ proliferation, migration, and Wnt/β-catenin signaling was analyzed after RBM5 knockdown and overexpression. Results: The expression level of RBM5 mRNA and protein was significantly lower in MB than that in adjacent normal control tissues, and low RBM5 expression was significantly associated with reduced OS (p = 0.034). RBM5 knockdown induced Daoy and ONS-76 cells proliferation, while RBM5 overexpression repressed cell proliferation and migration in vitro (all p < 0.05). β-Catenin, LEF1, and cyclin D1 mRNA levels were upregulated, while DKK1 expression was downregulated in Daoy cells following RBM5 knockdown. Conclusion: RBM5 may function as a tumor suppressor in MB by regulating Wnt/β-catenin signaling, and its reduced expression is associated with lower OS.

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