Neonatal neuronal WWOX gene therapy rescues Wwox null phenotypes

Developmental epileptic encephalopathy caused by homozygosity of a c.172+1G>C variant in the WWOX gene

BACKGROUND

Variations in the WWOX gene have been identified as the leading cause of several central nervous system disorders. However, most previous reports have focused on the description of clinical phenotype, neglecting functional verification. Herein, we presented a case of a patient with developmental epileptic encephalopathy (DEE) caused by WWOX gene variation.

CASE PRESENTATION

Our patient was a 13-month-old girl with abnormal facial features, including facial hypotonia, arched eyebrows, a broad nose, and a depressed nasal bridge. She also had sparse and yellow hair, a low anterior hairline, and a short neck. Before the age of 8 months, she was suffering from mild seizures. Her developmental delay gradually worsened, and she suffered infantile spasms. After treatment with vigabatrin, seizures subsided. WWOX gene homozygous variation c.172+1G>C was identified using whole exome sequencing. Further minigene assay confirmed that the variation site affected splicing, causing protein truncation and affecting its function.

CONCLUSION

Clinical phenotype and minigene results suggest that WWOX gene homozygous variation c.172+1G>C can cause severe DEE. We also concluded that vigabatrin can effectively treat seizures.

Proteins and Transcriptional Dysregulation of the Brain Extracellular Matrix in Parkinson's Disease: A Systematic Review

The extracellular matrix (ECM) of the brain is a dynamic structure made up of a vast network of bioactive macromolecules that modulate cellular events. Structural, organizational, and functional changes in these macromolecules due to genetic variation or environmental stressors are thought to affect cellular functions and may result in disease. However, most mechanistic studies to date usually focus on the cellular aspects of diseases and pay less attention to the relevance of the processes governing the dynamic nature of the extracellular matrix in disease pathogenesis. Thus, due to the ECM's diversified biological roles, increasing interest in its involvement in disease, and the lack of sufficient compiled evidence regarding its relationship with Parkinson's disease (PD) pathology, we aimed to compile the existing evidence to boost the current knowledge on the area and provide refined guidance for the future research. Here, in this review, we gathered postmortem brain tissue and induced pluripotent stem cell (iPSC)-related studies from PubMed and Google Scholar to identify, summarize and describe common macromolecular alterations in the expression of brain ECM components in Parkinson's disease (PD). A literature search was conducted up until 10 February 2023. The overall hits from the database and manual search for proteomic and transcriptome studies were 1243 and 1041 articles, respectively. Following a full-text review, 10 articles from proteomic and 24 from transcriptomic studies were found to be eligible for inclusion. According to proteomic studies, proteins such as collagens, fibronectin, annexins, and tenascins were recognized to be differentially expressed in Parkinson's disease. Transcriptomic studies displayed dysregulated pathways including ECM-receptor interaction, focal adhesion, and cell adhesion molecules in Parkinson's disease. A limited number of relevant studies were accessed from our search, indicating that much work remains to be carried out to better understand the roles of the ECM in neurodegeneration and Parkinson's disease. However, we believe that our review will elicit focused primary studies and thus support the ongoing efforts of the discovery and development of diagnostic biomarkers as well as therapeutic agents for Parkinson's disease.

Antineoplastic Nature of WWOX in Glioblastoma Is Mainly a Consequence of Reduced Cell Viability and Invasion

Following the discovery of WWOX, research has moved in many directions, including the role of this putative tumor suppressor in the central nervous system and related diseases. The task of determining the nature of WWOX in glioblastoma (GBM) is still considered to be at the initial stage; however, the influence of this gene on the GBM malignant phenotype has already been reported. Because most of the available in vitro research does not consider several cellular GBM models or a wide range of investigated biological assays, the present study aimed to determine the main processes by which WWOX exhibits anticancer properties in GBM, while taking into account the phenotypic heterogeneity between cell lines. Ectopic WWOX overexpression was studied in T98G, DBTRG-05MG, U251MG, and U87MG cell lines that were compared with the use of assays investigating cell viability, proliferation, apoptosis, adhesion, clonogenicity, three-dimensional and anchorage-independent growth, and invasiveness. Observations presenting the antineoplastic properties of WWOX were consistent for T98G, U251MG, and U87MG. Increased proliferation and tumor growth were noted in WWOX-overexpressing DBTRG-05MG cells. A possible explanation for this, arrived at via bioinformatics tools, was linked to the TARDBP transcription factor and expression differences of USP25 and CPNE2 that regulate EGFR surface abundance. Collectively, and despite various cell line-specific circumstances, WWOX exhibits its anticancer nature mainly via a reduction of cell viability and invasiveness of glioblastoma.

Expansion of the clinical and molecular spectrum of WWOX-related epileptic encephalopathy

WWOX biallelic loss-of-function pathogenic single nucleotide variants (SNVs) and copy number variants (CNVs) including exonic deletions and duplications cause WWOX-related epileptic encephalopathy (WOREE) syndrome. This disorder is characterized by refractory epilepsy, axial hypotonia, peripheral hypertonia, progressive microcephaly, and premature death. Here we report five patients with WWOX biallelic predicted null variants identified by exome sequencing (ES), genome sequencing (GS), and/or chromosomal microarray analysis (CMA). SNVs and intragenic deletions of one or more exons were commonly reported in WOREE syndrome patients which made the genetic diagnosis challenging and required a combination of different diagnostic technologies. These patients presented with severe, developmental and epileptic encephalopathy (DEE), and other cardinal features consistent with WOREE syndrome. This report expands the clinical phenotype associated with this condition, including failure to thrive in most patients and epilepsy that responded to a ketogenic diet in three patients. Dysmorphic features and abnormal prenatal findings were not commonly observed. Additionally, recurrent pancreatitis and sensorineural hearing loss each were observed in single patients. In summary, these phenotypic features broaden the clinical spectrum of WOREE syndrome.

Rodent Models of Audiogenic Epilepsy: Genetic Aspects, Advantages, Current Problems and Perspectives

Animal models of epilepsy are of great importance in epileptology. They are used to study the mechanisms of epileptogenesis, and search for new genes and regulatory pathways involved in the development of epilepsy as well as screening new antiepileptic drugs. Today, many methods of modeling epilepsy in animals are used, including electroconvulsive, pharmacological in intact animals, and genetic, with the predisposition for spontaneous or refractory epileptic seizures. Due to the simplicity of manipulation and universality, genetic models of audiogenic epilepsy in rodents stand out among this diversity. We tried to combine data on the genetics of audiogenic epilepsy in rodents, the relevance of various models of audiogenic epilepsy to certain epileptic syndromes in humans, and the advantages of using of rodent strains predisposed to audiogenic epilepsy in current epileptology.

WWOX-Related Neurodevelopmental Disorders: Models and Future Perspectives

The WW domain-containing oxidoreductase (WWOX) gene was originally discovered as a putative tumor suppressor spanning the common fragile site FRA16D, but as time has progressed the extent of its pleiotropic function has become apparent. At present, WWOX is a major source of interest in the context of neurological disorders, and more specifically developmental and epileptic encephalopathies (DEEs). This review article aims to introduce the many model systems used through the years to study its function and roles in neuropathies. Similarities and fundamental differences between rodent and human models are discussed. Finally, future perspectives and promising research avenues are suggested.