Transcriptional Regulator ZEB2 Is Essential for Bergmann Glia Development

Yin Yang 1 controls cerebellar astrocyte maturation

Diverse subpopulations of astrocytes tile different brain regions to accommodate local requirements of neurons and associated neuronal circuits. Nevertheless, molecular mechanisms governing astrocyte diversity remain mostly unknown. We explored the role of a zinc finger transcription factor Yin Yang 1 (YY1) that is expressed in astrocytes. We found that specific deletion of YY1 from astrocytes causes severe motor deficits in mice, induces Bergmann gliosis, and results in simultaneous loss of GFAP expression in velate and fibrous cerebellar astrocytes. Single cell RNA-seq analysis showed that YY1 exerts specific effects on gene expression in subpopulations of cerebellar astrocytes. We found that although YY1 is dispensable for the initial stages of astrocyte development, it regulates subtype-specific gene expression during astrocyte maturation. Moreover, YY1 is continuously needed to maintain mature astrocytes in the adult cerebellum. Our findings suggest that YY1 plays critical roles regulating cerebellar astrocyte maturation during development and maintaining a mature phenotype of astrocytes in the adult cerebellum.

ZEB2 haploinsufficient Mowat-Wilson syndrome induced pluripotent stem cells show disrupted GABAergic transcriptional regulation and function

Mowat-Wilson syndrome (MWS) is a severe neurodevelopmental disorder caused by heterozygous variants in the gene encoding transcription factor ZEB2. Affected individuals present with structural brain abnormalities, speech delay and epilepsy. In mice, conditional loss of Zeb2 causes hippocampal degeneration, altered migration and differentiation of GABAergic interneurons, a heterogeneous population of mainly inhibitory neurons of importance for maintaining normal excitability. To get insights into GABAergic development and function in MWS we investigated ZEB2 haploinsufficient induced pluripotent stem cells (iPSC) of MWS subjects together with iPSC of healthy donors. Analysis of RNA-sequencing data at two time points of GABAergic development revealed an attenuated interneuronal identity in MWS subject derived iPSC with enrichment of differentially expressed genes required for transcriptional regulation, cell fate transition and forebrain patterning. The ZEB2 haploinsufficient neural stem cells (NSCs) showed downregulation of genes required for ventral telencephalon specification, such as FOXG1, accompanied by an impaired migratory capacity. Further differentiation into GABAergic interneuronal cells uncovered upregulation of transcription factors promoting pallial and excitatory neurons whereas cortical markers were downregulated. The differentially expressed genes formed a neural protein-protein network with extensive connections to well-established epilepsy genes. Analysis of electrophysiological properties in ZEB2 haploinsufficient GABAergic cells revealed overt perturbations manifested as impaired firing of repeated action potentials. Our iPSC model of ZEB2 haploinsufficient GABAergic development thus uncovers a dysregulated gene network leading to immature interneurons with mixed identity and altered electrophysiological properties, suggesting mechanisms contributing to the neuropathogenesis and seizures in MWS.

A Glance at the Molecules That Regulate Oligodendrocyte Myelination

Oligodendrocyte (OL) myelination is a critical process for the neuronal axon function in the central nervous system. After demyelination occurs because of pathophysiology, remyelination makes repairs similar to myelination. Proliferation and differentiation are the two main stages in OL myelination, and most factors commonly play converse roles in these two stages, except for a few factors and signaling pathways, such as OLIG2 (Oligodendrocyte transcription factor 2). Moreover, some OL maturation gene mutations induce hypomyelination or hypermyelination without an obvious function in proliferation and differentiation. Herein, three types of factors regulating myelination are reviewed in sequence.

Epithelial Mesenchymal Transition and its transcription factors

Epithelial–mesenchymal transition or EMT is an extremely dynamic process involved in conversion of epithelial cells into mesenchymal cells, stimulated by an ensemble of signaling pathways, leading to change in cellular morphology, suppression of epithelial characters and acquisition of properties such as enhanced cell motility and invasiveness, reduced cell death by apoptosis, resistance to chemotherapeutic drugs etc. Significantly, EMT has been found to play a crucial role during embryonic development, tissue fibrosis and would healing, as well as during cancer metastasis. Over the years, work from various laboratories have identified a rather large number of transcription factors (TFs) including the master regulators of EMT, with the ability to regulate the EMT process directly. In this review, we put together these EMT TFs and discussed their role in the process. We have also tried to focus on their mechanism of action, their interdependency, and the large regulatory network they form. Subsequently, it has become clear that the composition and structure of the transcriptional regulatory network behind EMT probably varies based upon various physiological and pathological contexts, or even in a cell/tissue type-dependent manner.

miR-338-5p-ZEB2 axis in Diagnostic, Therapeutic Predictive and Prognostic Value of Gastric Cancer

MiRNAs have been widely reported to be involved in the occurrence and development of cancers. So far, some studies have revealed that miR-338-5p has the functions of tumorigenesis and tumor suppression. However, the role of miR-338-5p in the pathogenesis, progression and treatment of gastric cancer (GC) has not been reported. MiRNAs microarray analysis showed for the first time that miR-338-5p was significantly lower-expression in cisplin-resistant GC cells SGC7901/DDP, and cell viability assay and flow cytometry confirmed that overexpression of miR-338-5p could significantly increase cisplatin-sensitivity of SGC7901/DDP and BGC823 cells. Subsequently, we found that the expression of miR-338-5p in postoperative cancer tissues of GC patients was also significantly lower than the corresponding paracancer tissues. The expression of miR-338-5p in peripheral blood serum of GC patients is generally lower than that of healthy people. Moreover, the low expression of miR-338-5p in the cancer tissues and serum of GC patients was closely associated with larger tumor volume, lymph node metastasis, later stage, and even poorer survival, which was confirmed by close 5-year cases follow-up. ZEB2, as a predictive target of miR-338-5p, its expression was negatively regulated by miR-338-5p and can promote cisplatin-resistance in SGC7901/DDP and BGC823 cells. The expression of ZEB2 in cisplatin-resistant SGC7901/DDP cells and GC tissues were significantly higher than SGC7901 cells and paracancer tissues, respectively. Moreover, the expression of ZEB2 in tumor tissues was negatively correlated with miR-338-5p in tumor tissues and peripheral blood serum of GC patients, and the abnormally high expression of ZEB2 in prospective case studies is positively related with more serious clinical pathology and worse survival. More meaningfully, in a retrospective case study, we found that high ZEB2 expression predicts worse clinical efficacy of platinum chemotherapy. Thus, miR-338-5p-ZEB2 axis have novel diagnostic, therapeutic predictive, and prognostic value in GC patients.

Angelman Syndrome and Angelman-like Syndromes Share the Same Calcium-Related Gene Signatures

Angelman-like syndromes are a group of neurodevelopmental disorders that entail clinical presentation similar to Angelman Syndrome (AS). In our previous study, we showed that calcium signaling is disrupted in AS, and we identified calcium-target and calcium-regulating gene signatures that are able to differentiate between AS and their controls in different models. In the herein study, we evaluated these sets of calcium-target and calcium-regulating genes as signatures of AS-like and non-AS-like syndromes. We collected a number of RNA-seq datasets of various AS-like and non-AS-like syndromes and performed Principle Component Analysis (PCA) separately on the two sets of signature genes to visualize the distribution of samples on the PC1-PC2 plane. In addition to the evaluation of calcium signature genes, we performed differential gene expression analyses to identify calcium-related genes dysregulated in each of the studied syndromes. These analyses showed that the calcium-target and calcium-regulating signatures differentiate well between AS-like syndromes and their controls. However, in spite of the fact that many of the non-AS-like syndromes have multiple differentially expressed calcium-related genes, the calcium signatures were not efficient classifiers for non-AS-like neurodevelopmental disorders. These results show that features based on clinical presentation are reflected in signatures derived from bioinformatics analyses and suggest the use of bioinformatics as a tool for classification.

Transcriptome programs involved in the development and structure of the cerebellum

In the past two decades, mounting evidence has modified the classical view of the cerebellum as a brain region specifically involved in the modulation of motor functions. Indeed, clinical studies and engineered mouse models have highlighted cerebellar circuits implicated in cognitive functions and behavior. Furthermore, it is now clear that insults occurring in specific time windows of cerebellar development can affect cognitive performance later in life and are associated with neurological syndromes, such as Autism Spectrum Disorder. Despite its almost homogenous cytoarchitecture, how cerebellar circuits form and function is not completely elucidated yet. Notably, the apparently simple neuronal organization of the cerebellum, in which Purkinje cells represent the only output, hides an elevated functional diversity even within the same neuronal population. Such complexity is the result of the integration of intrinsic morphogenetic programs and extracellular cues from the surrounding environment, which impact on the regulation of the transcriptome of cerebellar neurons. In this review, we briefly summarize key features of the development and structure of the cerebellum before focusing on the pathways involved in the acquisition of the cerebellar neuron identity. We focus on gene expression and mRNA processing programs, including mRNA methylation, trafficking and splicing, that are set in motion during cerebellar development and participate to its physiology. These programs are likely to add new layers of complexity and versatility that are fundamental for the adaptability of cerebellar neurons.

ZEB2, the Mowat-Wilson Syndrome Transcription Factor: Confirmations, Novel Functions, and Continuing Surprises

After its publication in 1999 as a DNA-binding and SMAD-binding transcription factor (TF) that co-determines cell fate in amphibian embryos, ZEB2 was from 2003 studied by embryologists mainly by documenting the consequences of conditional, cell-type specific Zeb2 knockout (cKO) in mice. In between, it was further identified as causal gene causing Mowat-Wilson Syndrome (MOWS) and novel regulator of epithelial-mesenchymal transition (EMT). ZEB2's functions and action mechanisms in mouse embryos were first addressed in its main sites of expression, with focus on those that helped to explain neurodevelopmental and neural crest defects seen in MOWS patients. By doing so, ZEB2 was identified in the forebrain as the first TF that determined timing of neuro-/gliogenesis, and thereby also the extent of different layers of the cortex, in a cell non-autonomous fashion, i.e., by its cell-intrinsic control within neurons of neuron-to-progenitor paracrine signaling. Transcriptomics-based phenotyping of Zeb2 mutant mouse cells have identified large sets of intact-ZEB2 dependent genes, and the cKO approaches also moved to post-natal brain development and diverse other systems in adult mice, including hematopoiesis and various cell types of the immune system. These new studies start to highlight the important adult roles of ZEB2 in cell-cell communication, including after challenge, e.g., in the infarcted heart and fibrotic liver. Such studies may further evolve towards those documenting the roles of ZEB2 in cell-based repair of injured tissue and organs, downstream of actions of diverse growth factors, which recapitulate developmental signaling principles in the injured sites. Evident questions are about ZEB2's direct target genes, its various partners, and ZEB2 as a candidate modifier gene, e.g., in other (neuro)developmental disorders, but also the accurate transcriptional and epigenetic regulation of its mRNA expression sites and levels. Other questions start to address ZEB2's function as a niche-controlling regulatory TF of also other cell types, in part by its modulation of growth factor responses (e.g., TGFβ/BMP, Wnt, Notch). Furthermore, growing numbers of mapped missense as well as protein non-coding mutations in MOWS patients are becoming available and inspire the design of new animal model and pluripotent stem cell-based systems. This review attempts to summarize in detail, albeit without discussing ZEB2's role in cancer, hematopoiesis, and its emerging roles in the immune system, how intense ZEB2 research has arrived at this exciting intersection.

Little cells of the little brain: microglia in cerebellar development and function

Microglia are long-lived resident macrophages of the brain with diverse roles that span development, adulthood, and aging. Once thought to be a relatively homogeneous population, there is a growing recognition that microglia are highly specialized to suit their specific brain region. Cerebellar microglia represent an example of such specialization, exhibiting a dynamical, transcriptional, and immunological profile that differs from that of other microglial populations. Here we review the evidence that cerebellar microglia shape the cerebellar environment and are in turn shaped by it. We examine the roles microglia play in cerebellar function, development, and aging. The emerging findings on cerebellar microglia may also provide insights into disease processes involving cerebellar dysfunction.

Neurological Phenotype of Mowat-Wilson Syndrome

Mowat-Wilson Syndrome (MWS) (OMIM # 235730) is a rare disorder due to ZEB2 gene defects (heterozygous mutation or deletion). The ZEB2 gene is a widely expressed regulatory gene, extremely important for the proper prenatal development. MWS is characterized by a specific facial gestalt and multiple musculoskeletal, cardiac, gastrointestinal, and urogenital anomalies. The nervous system involvement is extensive and constitutes one of the main features in MWS, heavily affecting prognosis and life quality of affected individuals. This review aims to comprehensively organize and discuss the neurological and neurodevelopmental phenotype of MWS. First, we will describe the role of ZEB2 in the formation and development of the nervous system by reviewing the preclinical studies in this regard. ZEB2 regulates the neural crest cell differentiation and migration, as well as in the modulation of GABAergic transmission. This leads to different degrees of structural and functional impairment that have been explored and deepened by various authors over the years. Subsequently, the different neurological aspects of MWS (head and brain malformations, epilepsy, sleep disorders, and enteric and peripheral nervous system involvement, as well as developmental, cognitive, and behavioral features) will be faced one at a time and extensively examined from both a clinical and etiopathogenetic point of view, linking them to the ZEB2 related pathways.

Morphological and Calcium Signaling Alterations of Neuroglial Cells in Cerebellar Cortical Dysplasia Induced by Carmustine

Cortical dysplasias are alterations in the organization of the layers of the brain cortex due to problems in neuronal migration during development. The neuronal component has been widely studied in experimental models of cortical dysplasias. In contrast, little is known about how glia are affected. In the cerebellum, Bergmann glia (BG) are essential for neuronal migration during development, and in adult they mediate the control of fine movements through glutamatergic transmission. The aim of this study was to characterize the morphology and intracellular calcium dynamics of BG and astrocytes from mouse cerebellum and their modifications in a model of cortical dysplasia induced by carmustine (BCNU). Carmustine-treated mice were affected in their motor coordination and balance. Cerebellar dysplasias and heterotopias were more frequently found in lobule X. Morphology of BG cells and astrocytes was affected, as were their spontaneous [Ca²⁺]ⁱ transients in slice preparation and in vitro.

ACSA-2 and GLAST classify subpopulations of multipotent and glial-restricted cerebellar precursors

The formation of the cerebellum is highly coordinated to obtain its characteristic morphology and all cerebellar cell types. During mouse postnatal development, cerebellar progenitors with astroglial‐like characteristics generate mainly astrocytes and oligodendrocytes. However, a subset of astroglial‐like progenitors found in the prospective white matter (PWM) produces astroglia and interneurons. Characterizing these cerebellar astroglia‐like progenitors and distinguishing their developmental fates is still elusive. Here, we reveal that astrocyte cell surface antigen‐2 (ACSA‐2), lately identified as ATPase, Na+/K+ transporting, beta 2 polypeptide, is expressed by glial precursors throughout postnatal cerebellar development. In contrast to common astrocyte markers, ACSA‐2 appears on PWM cells but is absent on Bergmann glia (BG) precursors. In the adult cerebellum, ACSA‐2 is broadly expressed extending to velate astrocytes in the granular layer, white matter astrocytes, and to a lesser extent to BG. Cell transplantation and transcriptomic analysis revealed that marker staining discriminates two postnatal progenitor pools. One subset is defined by the co‐expression of ACSA‐2 and GLAST and the expression of markers typical of parenchymal astrocytes. These are PWM precursors that are exclusively gliogenic. They produce predominantly white matter and granular layer astrocytes. Another subset is constituted by GLAST positive/ACSA‐2 negative precursors that express neurogenic and BG‐like progenitor genes. This population displays multipotency and gives rise to interneurons besides all glial types, including BG. In conclusion, this work reports about ACSA‐2, a marker that in combination with GLAST enables for the discrimination and isolation of multipotent and glia‐committed progenitors, which generate different types of cerebellar astrocytes.

Temporarily Epigenetic Repression in Bergmann Glia Regulates the Migration of Granule Cells

Forming tight interaction with both Purkinje and granule cells (GCs), Bergmann glia (BG) are essential for cerebellar morphogenesis and neuronal homeostasis. However, how BG act in this process is unclear without comprehensive transcriptome landscape of BG. Here, high temporal-resolution investigation of transcriptomes with FACS-sorted BG revealed the dynamic expression of genes within given functions and pathways enabled BG to assist neural migration and construct neuron-glia network. It is found that the peak time of GCs migration (P7-10) strikingly coincides with the downregulation of extracellular matrix (ECM) related genes, and the disruption of which by Setdb1 ablation at P7-10 in BG leads to significant migration defect of GCs emphasizing the criticality of Nfix-Setdb1 mediated H3K9me3 repressive complex for the precise regulation of GCs migration in vivo. Thus, BG's transcriptomic landscapes offer an insight into the mechanism by which BG are in depth integrated in cerebellar neural network.

Zeb2 Is a Regulator of Astrogliosis and Functional Recovery after CNS Injury

The astrocytic response to injury is characterized on the cellular level, but our understanding of the molecular mechanisms controlling the cellular processes is incomplete. The astrocytic response to injury is similar to wound-healing responses in non-neural tissues that involve epithelial-to-mesenchymal transitions (EMTs) and upregulation in ZEB transcription factors. Here we show that injury-induced astrogliosis increases EMT-related genes expression, including Zeb2, and long non-coding RNAs, including Zeb2os, which facilitates ZEB2 protein translation. In mouse models of either contusive spinal cord injury or transient ischemic stroke, the conditional knockout of Zeb2 in astrocytes attenuates astrogliosis, generates larger lesions, and delays the recovery of motor function. These findings reveal ZEB2 as an important regulator of the astrocytic response to injury and suggest that astrogliosis is an EMT-like process, which provides a conceptual connection for the molecular and cellular similarities between astrogliosis and wound-healing responses in non-neural tissue.

PRDM16 regulates a temporal transcriptional program to promote progression of cortical neural progenitors

Radial glia (RG) in the neocortex sequentially generate distinct subtypes of projection neurons, accounting for the diversity and complex assembly of cortical neural circuits. Mechanisms that drive the rapid and precise temporal progression of RG are beginning to be elucidated. Here, we reveal that the RG-specific transcriptional regulator PRDM16 promotes the transition of early to late phase of neurogenesis in the mouse neocortex. Loss of Prdm16 delays the timely progression of RG, leading to defective cortical laminar organization. Our genomic analyses demonstrate that PRDM16 regulates a subset of genes that are dynamically expressed between early and late neurogenesis. We show that PRDM16 suppresses target gene expression through limiting chromatin accessibility of permissive enhancers. We further confirm that crucial target genes regulated by PRDM16 are neuronal specification genes, cell cycle regulators and molecules required for neuronal migration. These findings provide evidence to support the finding that neural progenitors temporally shift the gene expression program to achieve neural cell diversity.

Systematic analysis of purified astrocytes after SCI unveils Zeb2os function during astrogliosis

Spinal cord injury (SCI) is one of the most devastating neural injuries without effective therapeutic solutions. Astrocytes are the predominant component of the scar. Understanding the complex contributions of reactive astrocytes to SCI pathophysiologies is fundamentally important for developing therapeutic strategies. We have studied the molecular changes in the injury environment and the astrocyte-specific responses by astrocyte purification from injured spinal cords from acute to chronic stages. In addition to protein-coding genes, we have systematically analyzed the expression profiles of long non-coding RNAs (lncRNAs) (>200 bp), which are regulatory RNAs that play important roles in the CNS. We have identified a highly conserved lncRNA, Zeb2os, and demonstrated using functional assays that it plays an important role in reactive astrogliosis through the Zeb2os/Zeb2/Stat3 axis. These studies provide valuable insights into the molecular basis of reactive astrogliosis and fill the knowledge gap regarding the function(s) of lncRNAs in astrogliosis and SCI.

Objective detection of microtremors in netrin-G2 knockout mice

BACKGROUND

Essential tremor is the most prevalent movement disorder and is thought to be caused by abnormalities in the cerebellar system; however, its underlying neural mechanism is poorly understood. In this study, we found that mice lacking netrin-G2, a cell adhesion molecule which is expressed in neural circuits related to the cerebellar system, exhibited a microtremor resembling an essential tremor. However, it was difficult to quantify microtremors in netrin-G2 KO mice.

NEW METHOD

We developed a new tremor detector which can quantify the intensity and frequency of a tremor.

RESULTS

Using this system, we were able to characterize both the microtremors in netrin-G2 KO mice and low-dose harmaline-induced tremors which, to date, had been difficult to detect. Alcohol and anti-tremor drugs, which are effective in decreasing the symptoms of essential tremor in patients, were examined in netrin-G2 KO mice. We found that some drugs lowered the tremor frequency, but had little effect on tremor intensity. Forced swim as a stress stimulus in netrin-G2 KO mice dramatically enhanced tremor symptoms.

COMPARISON WITH EXISTING METHODS

The detection performance even for tremors induced by low-dose harmaline was similar to that in previous studies or more sensitive than the others.

CONCLUSIONS

Microtremors in netrin-G2 KO mice are reliably and quantitatively detected by our new tremor detection system. We found different effects of medicines and factors between human essential tremors and microtremors in netrin-G2 KO mice, suggesting that the causations, mechanisms, and symptoms of tremors vary and are heterogeneous, and the objective analyses are required.

Neuropathology of Mowat-Wilson Syndrome

Mowat-Wilson syndrome (MWS) is a syndromic form of Hirschsprung disease that is characterized by variable degrees of intellectual disability, characteristic facial dysmorphism, and a diverse set of other congenital malformations due to haploinsufficiency of ZEB2. A variety of brain malformations have been described in neuroimaging studies of MWS patients, and the role of ZEB2 in the brain has been studied in a multitude of genetically engineered mouse models that are now available. However, a paucity of autopsy information limits our ability to correlate data from neuroimaging studies and animal models with actual MWS patient tissues. Here, we report the autopsy neuropathology of a 19-year-old male patient with MWS. Autopsy neuropathology findings correlated well with the reported MWS neuroimaging data and are in keeping with data from genetically engineered MWS mouse models. This autopsy enhances our understanding of ZEB2 function in human brain development and demonstrates the reliability of MWS murine models.

Cerebellar Astrocytes: Much More Than Passive Bystanders In Ataxia Pathophysiology

Ataxia is a neurodegenerative syndrome, which can emerge as a major element of a disease or represent a symptom of more complex multisystemic disorders. It comprises several forms with a highly variegated etiology, mainly united by motor, balance, and speech impairments and, at the tissue level, by cerebellar atrophy and Purkinje cells degeneration. For this reason, the contribution of astrocytes to this disease has been largely overlooked in the past. Nevertheless, in the last few decades, growing evidences are pointing to cerebellar astrocytes as crucial players not only in the progression but also in the onset of distinct forms of ataxia. Although the current knowledge on this topic is very fragmentary and ataxia type-specific, the present review will attempt to provide a comprehensive view of astrocytes’ involvement across the distinct forms of this pathology. Here, it will be highlighted how, through consecutive stage-specific mechanisms, astrocytes can lead to non-cell autonomous neurodegeneration and, consequently, to the behavioral impairments typical of this disease. In light of that, treating astrocytes to heal neurons will be discussed as a potential complementary therapeutic approach for ataxic patients, a crucial point provided the absence of conclusive treatments for this disease.

C2H2-Type Zinc Finger Proteins in Brain Development, Neurodevelopmental, and Other Neuropsychiatric Disorders: Systematic Literature-Based Analysis

Neurodevelopmental disorders (NDDs) are multifaceted pathologic conditions manifested with intellectual disability, autistic features, psychiatric problems, motor dysfunction, and/or genetic/chromosomal abnormalities. They are associated with skewed neurogenesis and brain development, in part through dysfunction of the neural stem cells (NSCs) where abnormal transcriptional regulation on key genes play significant roles. Recent accumulated evidence highlights C₂H₂-type zinc finger proteins (C₂H₂-ZNFs), the largest transcription factor family in humans, as important targets for the pathologic processes associated with NDDs. In this review, we identified their significant accumulation (74 C₂H₂-ZNFs: ~10% of all human member proteins) in brain physiology and pathology. Specifically, we discuss their physiologic contribution to brain development, particularly focusing on their actions in NSCs. We then explain their pathologic implications in various forms of NDDs, such as morphological brain abnormalities, intellectual disabilities, and psychiatric disorders. We found an important tendency that poly-ZNFs and KRAB-ZNFs tend to be involved in the diseases that compromise gross brain structure and human-specific higher-order functions, respectively. This may be consistent with their characteristic appearance in the course of species evolution and corresponding contribution to these brain activities.

Genetic interaction screen for severe neurodevelopmental disorders reveals a functional link between Ube3a and Mef2 in Drosophila melanogaster

Neurodevelopmental disorders (NDDs) are clinically and genetically extremely heterogeneous with shared phenotypes often associated with genes from the same networks. Mutations in TCF4, MEF2C, UBE3A, ZEB2 or ATRX cause phenotypically overlapping, syndromic forms of NDDs with severe intellectual disability, epilepsy and microcephaly. To characterize potential functional links between these genes/proteins, we screened for genetic interactions in Drosophila melanogaster. We induced ubiquitous or tissue specific knockdown or overexpression of each single orthologous gene (Da, Mef2, Ube3a, Zfh1, XNP) and in pairwise combinations. Subsequently, we assessed parameters such as lethality, wing and eye morphology, neuromuscular junction morphology, bang sensitivity and climbing behaviour in comparison between single and pairwise dosage manipulations. We found most stringent evidence for genetic interaction between Ube3a and Mef2 as simultaneous dosage manipulation in different tissues including glia, wing and eye resulted in multiple phenotype modifications. We subsequently found evidence for physical interaction between UBE3A and MEF2C also in human cells. Systematic pairwise assessment of the Drosophila orthologues of five genes implicated in clinically overlapping, severe NDDs and subsequent confirmation in a human cell line revealed interactions between UBE3A/Ube3a and MEF2C/Mef2, thus contributing to the characterization of the underlying molecular commonalities.

The crucial role of ZEB2: From development to epithelial-to-mesenchymal transition and cancer complexity

Zinc finger E-box binding homeobox 2 (ZEB2) is a DNA-binding transcription factor, which is mainly involved in epithelial-to-mesenchymal transition (EMT). EMT is a conserved process during which mature and adherent epithelial-like state is converted into a mobile mesenchymal state. Emerging data indicate that ZEB2 plays a pivotal role in EMT-induced processes such as development, differentiation, and malignant mechanisms, for example, drug resistance, cancer stem cell-like traits, apoptosis, survival, cell cycle arrest, tumor recurrence, and metastasis. In this regard, the understanding of mentioned subjects in the development of normal and cancerous cells could be helpful in cancer complexity of diagnosis and therapy. In this study, we review recent findings about the biological properties of ZEB2 in healthy and cancerous states to find new approaches for cancer treatment.

MicroRNA‑30a regulates cell proliferation, migration, invasion and apoptosis in human nasopharyngeal carcinoma via targeted regulation of ZEB2

MicroRNA-30a (miR-30a) was previously reported to serve as a tumor suppressor able to inhibit the development and progression of certain types of cancer. A number of previous studies demonstrated that zinc finger E-box binding homeobox 2 (ZEB2) may be regulated by miR-30a in clear cell renal cell carcinoma and breast cancer. However, the function of miR-30a in human nasopharyngeal carcinoma (NPC) remains unclear. The present study aimed to investigate the association between miR-30a and ZEB2 in NPC. Therefore, the expression levels of miR-30a and ZEB2 were measured in human NPC cells and tissues from patients with NPC, and the present results suggested that the expression level of miR-30a was significantly decreased in NPC tissues compared with paracancerous tissues. The direct interaction between miR-30a and the untranslated region of ZEB2 was examined using the dual-luciferase reporter assay, and ZEB2 was identified as a direct target of miR-30a. Additionally, the effects of miR-30a and ZEB2 overexpression on cell proliferation, migration, invasion and apoptosis were additionally investigated. Functional experiments identified that overexpression of miR-30a increased apoptosis and suppressed cell proliferation, cell migration and cell invasion by directly targeting ZEB2. Collectively, the present study suggested that miR-30a may serve an important role in the progression of NPC and may represent a novel target for the treatment of patients with NPC.

[Clinical and genetic features of Mowat-Wilson syndrome: an analysis of 3 cases]

Mowat-Wilson syndrome (MWS) is a rare autosomal dominant genetic disease caused by zinc finger E-box-binding homeobox 2 (ZEB2) gene mutation and has various clinical manifestations including intellectual disability/global developmental delay, unusual facies and multiple congenital malformations. This article reports the clinical features and gene mutations of three children diagnosed with MWS by ZEB2 gene analysis. All three children had Hirschsprung disease and unusual facies. One child died of severe heart failure and pneumonia at the age of 4 months. Global developmental delay was not discovered by her parents due to her young age. The other two children had severe global developmental delay. All three children carried a de novo heterozygous nonsense mutation in the ZEB2 gene, among which c.756C>A (p.Y252X) had not been reported before. Such mutations produced truncated proteins and were highly pathogenic. MWS is presented with strong clinical and genetic heterogeneity. Clinicians should consider the possibility of MWS when a child has unusual facies of MWS, intellectual disability/global developmental delay and multiple congenital malformations. Gene detection helps to make a confirmed diagnosis.

Lupeol inhibits LPS-induced neuroinflammation in cerebellar cultures and induces neuroprotection associated to the modulation of astrocyte response and expression of neurotrophic and inflammatory factors

In the central nervous system (CNS), neuroinflammation, especially that modulated by the cell response of astrocytes and microglia, is associated with damage to neurons in neurodegenerative disorders such as Parkinson's disease, Alzheimer's disease and, Multiple Sclerosis. Lupeol is a dietary triterpene that has demonstrated biological activities as antioxidant. This study investigated the anti-inflammatory and neuroprotective effects of lupeol in an in vitro model of neuroinflammation in primary cerebellar cultures. Cultures were obtained from 6-day-old Wistar rats, subjected to inflammatory damage with lipopolysaccharide (LPS, 1 μg/mL) and treated with lupeol (0.1 μM). We observed, after a 48-hour treatment, through Fluorjade-B staining and immunocytochemistry (ICQ) for βIII-tubulin, that lupeol induced neuroprotection in cultures submitted to inflammatory damage. On the other hand, through ICQ for GFAP, it was possible to observe that lupeol modulated the astrocyte morphology for Bergmann glia-like phenotype and, especially for velate astrocyte-like phenotype, both phenotypes associated with the neuroprotective profile. Moreover, RT-qPCR analysis showed that lupeol induced the down-regulation of the mRNA expression for proinflammatory markers TNF, iNOS and NLRP3, as well as the production of nitric oxide (method of Greiss), which were up-regulated by LPS, and also induced up-regulation of the mRNA expression for arginase and IL-6 mRNA. In addition, lupeol induced up-regulation of mRNA expression for neurotrophins GDNF and NGF and also for the sonic hedgehog-Gli pathway. Together, these results lead to the conclusion that lupeol inhibits neuroinflammation in cerebellar cultures and induces neuroprotection associated with the modulation of astrocyte response and expression of neurotrophic and inflammatory factors.

Role of Zeb2/Sip1 in neuronal development

Zeb2 (Sip1, Zfhx1b) is a transcription factor that plays essential role in neuronal development. Sip1 mutation in humans was shown to cause Mowat-Wilson syndrome, a syndromic form of Hirschprung's disease. Affected individuals exhibit multiple severe neurodevelopmental defects. Zeb2 can act as both transcriptional repressor and activator. It controls expression of a wide number of genes that regulate various aspects of neuronal development. This review addresses the molecular pathways acting downstream of Zeb2 that cause brain development disorders.