Erythropoietin (EPO) is a hematopoietic growth factor that stimulates proliferation and differentiation of erythroid precursor cells and is also known to exert neurotrophic activity in the central nervous system (CNS). However, little is known about expression of EPO and EPO receptor (EPOR) in human CNS tissues. In the present study, we investigated the effects of proinflammatory cytokines on EPO and EPOR expression in highly purified cultures of human neurons, astrocytes, microglia, and oligodendrocytes using reverse transcription-polymerase chain reaction (RT-PCR) and enzyme-linked immunosorbent assay (ELISA). EPO mRNA was demonstrated only in human astrocytes, while EPOR expression was found in human neurons, astrocytes, and microglia. Neither EPO nor EPOR expression was found in oligodendrocytes. In human astrocytes, EPO mRNA and secreted EPO protein levels were downregulated after exposure to proinflammatory cytokines (IL-1beta, IL-6, or TNF-alpha). In human neurons, TNF-alpha treatment markedly increased EPOR expression. These results suggest that proinflammatory cytokines regulate expression of EPO and EPOR in human neurons, astrocytes, and microglia and further facilitate interactions among different cell types in the human CNS.
Our study confirmed that SCN2A mutations are an important genetic cause of OS. Given the wide clinical spectrum associated with SCN2A mutations, genetic testing for SCN2A should be considered for children with different epileptic conditions.
Summary:Purpose: Mitogenic effects of seizures on granule cell progenitors in the dentate gyrus were studied in two rat models of epilepsy. We investigated which stage of epileptogenesis is critical for eliciting progenitor cell division and whether seizure-induced neuronal degeneration is responsible for the enhancement of progenitor cell division.Methods: Seizures were induced by either kainic acid (KA) administration or electrical kindling. Neurogenesis of dentate granule cells was evaluated using the bromodeoxyuridine (BrdU) labeling method, and neuronal degeneration was assessed by in situ DNA fragmentation analysis.Results: After injection of KA, the number of BrdU-positive granule cells began to increase at day 3 after the treatment, peaked at day 5 , and returned to baseline at day 10. By day 13, the values were lower than control. After kindling, the number of BrdU-positive cells began to increase after five consecutive experiences of stage I seizures. The increase occurred from day 1 to day 3 after the last electrical stimulation, but returned to baseline by day 7. After generalized seizures were well established, repeated stimulation did not facilitate division of granule cell progenitors. DNA fragmentation was noted in pyramidal neurons in the CA1, CA3, and hilus regions at 18 h after KA injection, but not in the kindling model.Conclusions: These observations indicate that a mechanism in epileptogenesis boosts dentate progenitor cell division, but progenitor cells may become unreactive to prolonged generalized seizures. Pyramidal neuronal degeneration is not necessary for triggering the upregulation. It is suggested thal newly born granule cells may play a role in the network reorganization that occurs during epileptogenesis. Key Words: Kainic acidKindling-Neurogenesis-Bromodeoxyuridine-DNA fragmentation.Accumulating evidence reveals that generalized seizures can produce both degenerative and regenerative structural changes in the hippocampus. They include neuronal degeneration, mossy fiber synaptic reorganization, and increased neurogenesis of dentate granule cells. Hippocampal sclerosis is the most commonly encountered lesion in temporal lobe epilepsy, which is associated with a marked loss of hippocampal neurons (1).Recent immunocytochemical studies suggest that the reorganization of dentate granule cell axons, the mossy fibers, occurs in human epileptic hippocampus (2,3) and in animal models of epilepsy (4,5). Mossy fiber collat-
We document the protocols and methods for the production of immortalized cell lines of human neural stem cells from the human fetal central nervous system (CNS) cells by using a retroviral vector encoding v-myc oncogene. One of the human neural stem cell lines (HB1.F3) was found to express nestin and other specific markers for human neural stem cells, giving rise to three fundamental cell types of the CNS: neurons, astrocytes, and oligodendrocytes. After transplantation into the brain of mouse model of stroke, implanted human neural stem cells were observed to migrate extensively from the site of implantation into other anatomical sites and to differentiate into neurons and glial cells.
Summary
Purpose
Early onset epileptic encephalopathies (EOEEs) are heterogeneous epileptic disorders caused by various abnormalities in causative genes including point mutations and copy number variations (CNVs). In this study, we performed targeted capture and sequencing of a subset of genes to detect point mutations and CNVs simultaneously.
Methods
We designed complementary RNA oligonucleotide probes against the coding exons of 35 known and potential candidate genes. We tested 68 unrelated patients, including 15 patients with previously detected mutations as positive controls. In addition to mutation detection by the Genome Analysis Toolkit, CNVs were detected by the relative depth of coverage ratio. All detected events were confirmed by Sanger sequencing or genomic microarray analysis.
Key Findings
We detected all positive control mutations. In addition, in 53 patients with EOEEs, we detected 12 pathogenic mutations, including 9 point mutations (2 nonsense, 3 splice‐site, and 4 missense mutations), 2 frameshift mutations, and one 3.7‐Mb microdeletion. Ten of the 12 mutations occurred de novo; the other two had been previously reported as pathogenic. The entire process of targeted capture, sequencing, and analysis required 1 week for the testing of up to 24 patients.
Significance
Targeted capture and sequencing enables the identification of mutations of all classes causing EOEEs, highlighting its usefulness for rapid and comprehensive genetic testing.
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