Induced pluripotent stem cells from patients with focal cortical dysplasia and refractory epilepsy

Abstract

Focal cortical dysplasia (FCD) is caused by numerous alterations, which can be divided into abnormalities of the cortical architecture and cytological variations; however, the exact etiology of FCD remains unknown. The generation of induced pluripotent stem cells (iPSCs) from the cells of patients with neurological diseases, and their subsequent tissue-specific differentiation, serves as an invaluable source for testing and studying the initial development and subsequent progression of diseases associated with the central nervous system. A total of 2 patients demonstrating seizures refractory to drug treatment, characterized as FCD Type IIb, were enrolled in the present study. Fibroblasts were isolated from residual skin fragments obtained from surgical treatment and from brain samples obtained during surgical resection. iPSCs were generated following exposure of fibroblasts to viral vectors containing POU class 5 homeobox 1 (OCT4), sex determining region Y-box 2 (SOX2), Kruppel-like factor 4 and c-MYC genes, and were characterized by immunohistochemical staining for the pluripotent markers homeobox protein NANOG, SOX2, OCT4, TRA1-60 and TRA1-81. The brain samples were tested with antibodies against protein kinase B (AKT), phosphorylated-AKT, mechanistic target of rapamycin (mTOR) and phosphorylated-mTOR. Analysis of the AKT/mTOR pathway revealed a statistically significant difference between the cerebral tissues of the two patients, which were of different ages (45 and 12 years old). Clones with the morphological features of embryonic cells were detected on the 13th day and were characterized following three subcultures. The positive staining characteristics of the embryonic cells confirmed the successful generation of iPSCs derived from the patients' fibroblasts. Therefore, the present study presents a method to obtain a useful cellular source that may help to understand embryonic brain development associated with FCD.

Oncogenic Notch Triggers Neoplastic Tumorigenesis in a Transition-Zone-like Tissue Microenvironment

“…However, in advanced Barrett esophagus, dysplastic cells can be detected, which also indicates a precancerous condition (Haggitt, 1994). Delamination and loss of apical-basal polarity are two important features to confirm a dysplasia (Lisovsky et al, 2009(Lisovsky et al, , 2010Marinowic et al, 2017;Tamori et al, 2016). Our studies show that gain of MMP1 can cause NICD-induced hyperplastic cells to become dysplastic in the anterior imaginal ring.…”

Protective Effects of Melatonin on the Skin: Future Perspectives

“…They observed an increase in the fibroblast growth factor-β (FGF-β), collagen type I, and fibronectin as well as high c-Myc and β-catenin expression following melatonin treatment of the epidermis and hair bulb in both normal and ovariectomy mice [87]. Previous studies have shown that c-Myc expression in fibroblasts can induce pluripotent stem cells in mouse skin [88] and is involved in reprogramming fibroblasts into induced pluripotent stem cells in different pathological situations [89,90]. In vitro studies have suggested that β-catenin is involved in positively regulating fibroblast proliferation during the wound healing process [91].…”

Teleost Fish and Organoids: Alternative Windows Into the Development of Healthy and Diseased Brains

“…Furthermore, IPSCs-derived neurons and forebrain organoids with LIS1 mutations exhibited proliferative defects, resembling also the zebrafish model (Iefremova et al, 2017); while the molecular mechanisms underlying focal dysplasia and tuberous sclerosis due to mutations in TSC1 and TSC2 have been studied in 2D and 3D cortical systems from human brain (Marinowic et al, 2017;Blair et al, 2018). Complementing the models available in zebrafish (Kedra et al, 2020) (Table 2), these studies showed an induced mTOR signaling and sustained gliogenesis as major contributors to the disease (Marinowic et al, 2017;Blair et al, 2018). Moreover, COs models of how migratory defects impact the correct formation of the cortex are also available (Buchsbaum et al, 2020).…”

“…Similarly, COs from patients with CDK5RAP2 mutations affecting centrosomes dynamics recapitulated the microcephaly which was difficult to analyze in mice models and provided valuable insights into the disease mechanism underlying altered neurogenesis (Lancaster et al, 2013). Furthermore, IPSCs-derived neurons and forebrain organoids with LIS1 mutations exhibited proliferative defects, resembling also the zebrafish model (Iefremova et al, 2017); while the molecular mechanisms underlying focal dysplasia and tuberous sclerosis due to mutations in TSC1 and TSC2 have been studied in 2D and 3D cortical systems from human brain (Marinowic et al, 2017;Blair et al, 2018). Complementing the models available in zebrafish (Kedra et al, 2020) (Table 2), these studies showed an induced mTOR signaling and sustained gliogenesis as major contributors to the disease (Marinowic et al, 2017;Blair et al, 2018).…”