scholarly journals The role of glia in epilepsy, intellectual disability, and other neurodevelopmental disorders in tuberous sclerosis complex

Author(s):  
Michael Wong

Abstract Background Tuberous sclerosis complex (TSC) is a genetic disorder characterized by severe neurological manifestations, including epilepsy, intellectual disability, autism, and a range of other behavioral and psychiatric symptoms, collectively referred to as TSC-associated neuropsychiatric disorders (TAND). Various tumors and hamartomas affecting different organs are the pathological hallmarks of the disease, especially cortical tubers of the brain, but specific cellular and molecular abnormalities, such as involving the mechanistic target of rapamycin (mTOR) pathway, have been identified that also cause or contribute to neurological manifestations of TSC independent of gross structural lesions. In particular, while neurons are immediate mediators of neurological symptoms, different types of glial cells have been increasingly recognized to play important roles in the phenotypes of TSC. Main body This review summarizes the literature supporting glial dysfunction from both mouse models and clinical studies of TSC. In particular, evidence for the role of astrocytes, microglia, and oligodendrocytes in the pathophysiology of epilepsy and TAND in TSC is analyzed. Therapeutic implications of targeting glia cells in developing novel treatments for the neurological manifestations of TSC are also considered. Conclusions Different types of glial cells have both cell autonomous effects and interactions with neurons and other cells that are involved in the pathophysiology of the neurological phenotype of TSC. Targeting glial-mediated mechanisms may represent a novel therapeutic approach for epilepsy and TAND in TSC patients.

2020 ◽  
Vol 2020 ◽  
pp. 1-4
Author(s):  
Claudia Ioana Borțea ◽  
Vlad Laurentiu David ◽  
Florina Stoica ◽  
Cezara Mureșan ◽  
Marioara Boia

Tuberous sclerosis complex is a multisystemic genetic disorder with high phenotypical variability. Its progress frequently brings along autism (61%), epilepsy, intellectual disability (45%), and neurocognitive impairment (Gipson and Johnston, 2017). We are considering the case of an infant suspected with tuberous sclerosis complex by imagistic investigation in the prenatal period. The pre- and postnatal ultrasound, fetal MRI, ophthalmoscopy, and dermatological and neurological examinations were used for diagnosis and follow-up. The seven major and minor criteria were regarded as sufficient for accurate diagnosis.


Cells ◽  
2021 ◽  
Vol 10 (1) ◽  
pp. 134
Author(s):  
Stephanie Dooves ◽  
Arianne J. H. van Velthoven ◽  
Linda G. Suciati ◽  
Vivi M. Heine

Tuberous sclerosis complex (TSC) is a genetic disease affecting the brain. Neurological symptoms like epilepsy and neurodevelopmental issues cause a significant burden on patients. Both neurons and glial cells are affected by TSC mutations. Previous studies have shown changes in the excitation/inhibition balance (E/I balance) in TSC. Astrocytes are known to be important for neuronal development, and astrocytic dysfunction can cause changes in the E/I balance. We hypothesized that astrocytes affect the synaptic balance in TSC. TSC patient-derived stem cells were differentiated into astrocytes, which showed increased proliferation compared to control astrocytes. RNA sequencing revealed changes in gene expression, which were related to epidermal growth factor (EGF) signaling and enriched for genes that coded for secreted or transmembrane proteins. Control neurons were cultured in astrocyte-conditioned medium (ACM) of TSC and control astrocytes. After culture in TSC ACM, neurons showed an altered synaptic balance, with an increase in the percentage of VGAT+ synapses. These findings were confirmed in organoids, presenting a spontaneous 3D organization of neurons and glial cells. To conclude, this study shows that TSC astrocytes are affected and secrete factors that alter the synaptic balance. As an altered E/I balance may underlie many of the neurological TSC symptoms, astrocytes may provide new therapeutic targets.


2021 ◽  
pp. 1-9
Author(s):  
Hamood N. Al Kindi ◽  
Ayman M. Ibrahim ◽  
Mohamed Roshdy ◽  
Besra S. Abdelghany ◽  
Dina Yehia ◽  
...  

Abstract Background: Rhabdomyoma is the most common cardiac tumour in children. It is usually associated with tuberous sclerosis complex caused by mutations in TSC-1 or TSC-2 genes. This tumour typically regresses by unknown mechanisms; however, it may cause inflow or outflow obstruction that necessitates urgent surgery. Here we investigate the clinical features and the genetic analysis of patients with tuberous sclerosis complex presenting with large rhabdomyoma tumours. We also investigate the potential role of autophagy and apoptosis in the pathogenesis of this tumour. Methods: All the patients with cardiac rhabdomyoma referred to Aswan Heart Centre from 2010 to 2018 were included in this study. Sanger sequencing was performed for coding exons and the flanking intronic regions of TSC1 and TSC2 genes. Histopathological evaluation, immunohistochemistry, and western blotting were performed with P62, LC3b, caspase3, and caspase7, to evaluate autophagic and apoptotic signaling. Results: Five patients were included and had the clinical features of tuberous sclerosis complex. Three patients, who were having obstructive tumours, were found to have pathogenic mutations in TSC-2. The expression of two autophagic markers, P62 and LC3b, and two apoptotic markers, caspase3 and caspase7, were increased in the tumour cells compared to normal surrounding myocardial tissue. Conclusion: All the patients with rhabdomyoma were diagnosed to have tuberous sclerosis complex. The patients who had pathogenic mutations in the TSC-2 gene had a severe disease form necessitating urgent intervention. We also demonstrate the potential role of autophagy and apoptosis as a possible mechanism for tumourigenesis and regression. Future studies will help in designing personalised treatment for cardiac rhabdomyoma.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Elieser Hitoshi Watanabe ◽  
Fernando Morbeck Almeida Coelho ◽  
Hilton Leão Filho ◽  
Bruno Eduardo Pedroso Balbo ◽  
Precil Diego Miranda de Menezes Neves ◽  
...  

AbstractRenal angiomyolipomas hemorrhage is associated with their size and vascular constitution. The effects of sirolimus on different components of angiomyolipomas was analyzed in patients with tuberous sclerosis complex, sporadic lymphangioleiomyomatosis and multiple sporadic angiomyolipomas. Thirty angiomyolipomas from 14 patients treated with sirolimus were retrospectively evaluated. A Hounsfield-unit threshold was used to classify angiomyolipomas in fat-rich, fat-poor and intermediate-fat tumors, and to categorize tumor compartments in fat rich, fat poor, intermediate fat and highly vascularized. Diameter variations were measured to assess the effects on aneurysmatic/ectatic vascular formations. Volume reduction following treatment with sirolimus was higher in fat-poor than fat-rich angiomyolipomas. Tumor reduction was mainly determined by decrease of the fat-poor and highly-vascularized compartments while the volume of the fat-rich compartment increased. Broad liposubstitution was observed in some tumors. A median reduction of 100% (75 to 100) in the diameter of aneurysmatic/ectatic vascular structures was observed. Our study showed that sirolimus reduces the size of angiomyolipomas by decreasing primarily their highly-vascularized and fat-poor compartments. This effect is associated with a remarkable reduction of tumoral aneurysms/ectatic vessels, revealing the likely mechanism responsible for the risk-decreasing effect of mTOR inhibitors on angiomyolipoma bleeding. These findings support the role of mTOR in the development of angiomyolipoma blood vessels.


2018 ◽  
Vol 3 (2) ◽  
pp. 276-280 ◽  
Author(s):  
Charlotte Tye ◽  
Laura E. Thomas ◽  
Julian R. Sampson ◽  
Julia Lewis ◽  
Finbar O'Callaghan ◽  
...  

2015 ◽  
Vol 80 ◽  
pp. 70-79 ◽  
Author(s):  
Bo Zhang ◽  
Jia Zou ◽  
Nicholas R. Rensing ◽  
Meihua Yang ◽  
Michael Wong

2021 ◽  
pp. 95-96
Author(s):  
Fabricio Andrés Lasso Andrade ◽  
Jorge Alejandro Cadena Arteaga ◽  
Ángela Maria Fajardo Arteaga ◽  
Viviana Lizeth Echeverry Morillo ◽  
David Alfredo Acevedo Vargas ◽  
...  

Tuberous Sclerosis Complex (TSC) also known as Bournneville disease. TSC is a multisystemic genetic disorder with autosomal dominant inheritance, of variable expression, which is mainly characterized by the presence of benign tumors or hamartomas in the nervous system and skin, but which may also be present in the heart, kidney, lung and other organs. The most frequent symptom is epilepsy, affecting 80-90% of patients with TSC which manifests itself in childhood between 1 to 3 years of age. We present a case of sporadic onset tuberous sclerosis with epilepsy that had a causal link with TSC after admission to the emergency room in a convulsive status.


Author(s):  
F. Scolari ◽  
B.F. Viola ◽  
L. Grazioli ◽  
L. Longa ◽  
N. Migone ◽  
...  

2019 ◽  
Vol 30 (4) ◽  
pp. 2199-2214
Author(s):  
Benoit Scherrer ◽  
Anna K Prohl ◽  
Maxime Taquet ◽  
Kush Kapur ◽  
Jurriaan M Peters ◽  
...  

Abstract Tuberous sclerosis complex (TSC) is a rare genetic disorder characterized by benign tumors throughout the body; it is generally diagnosed early in life and has a high prevalence of autism spectrum disorder (ASD), making it uniquely valuable in studying the early development of autism, before neuropsychiatric symptoms become apparent. One well-documented deficit in ASD is an impairment in face processing. In this work, we assessed whether anatomical connectivity patterns of the fusiform gyrus, a central structure in face processing, capture the risk of developing autism early in life. We longitudinally imaged TSC patients at 1, 2, and 3 years of age with diffusion compartment imaging. We evaluated whether the anatomical connectivity fingerprint of the fusiform gyrus was associated with the risk of developing autism measured by the Autism Observation Scale for Infants (AOSI). Our findings suggest that the fusiform gyrus connectivity captures the risk of developing autism as early as 1 year of age and provides evidence that abnormal fusiform gyrus connectivity increases with age. Moreover, the identified connections that best capture the risk of developing autism involved the fusiform gyrus and limbic and paralimbic regions that were consistent with the ASD phenotype, involving an increased number of left-lateralized structures with increasing age.


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