Browsing by Subject "Olig2"

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    Olig2 knockdown alleviates hypoxic- ischemic brain damage in newborn rats
    (Universidad de Murcia, Departamento de Biologia Celular e Histiologia, 2021) Yang, Lijun; Cui, Hong
    Objectives. Neuronal damage is an important pathological mechanism in neonatal hypoxic-ischemic brain damage (HIBD). We found in our previous studies that oligodendrocyte transcription factor 2 (Olig2) downregulation was able to increase cell survival in the brain. However, the specific mechanism has yet to be clarified. Methods. Sprague-Dawley rats aged 3 d were randomly divided into three groups: the normal control group, the Olig2-RNAi group, and the RNAi-negative control group. The normal control group received no treatment, the Olig2-RNAi group received the Olig2 RNAi adenovirus, and the RNAi-negative control group was given the control adenovirus after the completion of the HIBD model. Infarct lesions and their volumes were observed by triphenyltetrazolium chloride (TTC) staining 3 d after the completion of the adenovirus local injection. The condition of the tissue was characterized by hematoxylin-eosin staining 7 d after the model was established, and cell viability was determined by azure methylene blue staining. Subcellular damage was analyzed by transmission electron microscopy. Rotarod analysis was performed to detect moving behavior ability and an Morris water maze assay was conducted to evaluate the memory. Results. TTC staining showed a smaller brain injury area in the Olig2-RNAi group than in the RNAi-negative control group. Hematoxylin-eosin staining indicated the presence of severe cell injury in the hippocampal region after HIBD, which improved after Olig2 knockdown. Azure methylene blue staining and electron microscopy results suggested that the cells improved after Olig2 knockdown. The rats stayed longer on the rotating rod, and their latency in the water maze test was gradually shortened relative to that of the rats in the Olig2-RNAi negative control group. Conclusion. Olig2 knockdown can promote the repair of hypoxic-ischemic brain damage in newborn rats.
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    Oligodendroglial markers in the cuprizone model of CNS de- and remyelination
    (Universidad de Murcia. Departamento de Biología Celular e Histología, 2015) Salinas Tejedor, Laura; Gudi, Viktoria; Kucman, Valeria; Pul, Refik; Gingele, Stefan; Sühs, Kurt-Wolfram; Stangel, Martin; Skripuletz, Thomas
    y. Oligodendrocytes are the myelinating cells of the central nervous system. Since many studies of demyelinating diseases focus their research on this cell type, there is growing interest for obtaining reliable markers that can specifically recognize oligodendroglia. Established markers are the myelin-associated neurite outgrowth inhibitor (NogoA), the transcription factor Olig2, and the antibody CC-1, the latter being directed against the protein adenomatous polyposis coli (APC). Unfortunately, it has been discussed whether APC and Olig2 could recognize astrocytes under pathological conditions as well. Hence, we performed immunohistochemical studies using the oligodendroglial markers NogoA, APC, and Olig2 in a murine model of cuprizone induced demyelination. We have found that APC colocalizes with NogoA and does not co-localize with the astrocytic marker GFAP. Olig2 shows co-localization with APC but there is also a small population of Olig2/GFAP double positive cells. Some Olig2/GFAP double positive cells are found in the corpus callosum in a narrow time window in which oligodendrocyte precursor cells proliferate in this model. In other brain regions including the cerebral cortex and hippocampus and in all regions in untreated control mice double positive Olig2/GFAP cells do not occur. In conclusion, our results underline that APC and NogoA are reliable markers for detection of mature oligodendrocytes. Olig2 is a suitable marker to stain cells of oligodendroglial origin but could be combined with GFAP to exclude the GFAP positive population of cells from the quantification of oligodendroglia.
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    SOX10 and Olig2 as negative markers for the diagnosis of ependymomas: An immunohistochemical study of 98 glial tumors
    (Universidad de Murcia. Departamento de Biología Celular e Histología, 2016) Švajdler, Marián; Rychlý, Boris; Mezencev, Roman; Fröhlichová, Lucia; Bednárová, Antónia; Pataky, František; Daum, Ondřej
    SOX10 belongs to the family of transcription factors essential for the development of neural crest, peripheral nervous system and melanocytes. It is presently used in histopathology as a marker of melanocytic differentiation. SOX10 is expressed in normal brain tissue in oligodendrocytes, but the information about SOX10 expression in primary tumors of the central nervous system is quite limited. In this study, we examined the expression of SOX10 and Olig2 by immunohistochemistry in a series of 98 glial tumors and explored their specificity and sensitivity for differential diagnosis of ependymal vs non-ependymal tumors. In addition, we examined the expression of EMA and CD99 in ependymal tumors. SOX10 and Olig2 staining were scored as negative if no positive cells or only a few positive cells (typically up to 1-3%) were found. In all other instances, SOX10 or Olig2 staining was scored as positive. Out of 44 examined ependymal tumors none was found to express SOX10 and 7 specimens showed only a few SOX10-positive cells that likely corresponded to entrapped nonneoplastic oligodendrocytes. In contrast, non-ependymal tumors expressed SOX10 in 26/54 (48%) specimens. Olig2 was positive in 5 out of 44 ependymomas (11%) and 50 out of 54 (93%) non-ependymal tumors (astrocytomas and oligodendrogliomas). EMA and CD99 expression was found in 33/44 (75%) and 11/44 (25%) of ependymomas, respectively. SOX10-positivity rules out the diagnosis of ependymoma among other glial tumors with high confidence.