Filice, Federica Celio, Marco R. Babalian, Alexandre Blum, Walter Szabolcsi, Viktoria 2017-10-15 Aging-associated ependymal-cell pathologies can manifest as ventricular gliosis, ventricle enlargement, or ventricle stenosis. Ventricle stenosis and fusion of the lateral ventricle (LV) walls is associated with a massive decline of the proliferative capacities of the stem cell niche in the affected subventricular zone (SVZ) in aging mice. We examined the brains of adult C57BL/6 mice and found that ependymal cells located in the adhesions of the medial and lateral walls of the rostral LVs upregulated parvalbumin (PV) and displayed reactive phenotype, similarly to injury-reactive ependymal cells. However, PV+ ependymal cells in the LV-wall adhesions, unlike injury-reactive ones, did not express glial fibrillary acidic protein. S100B+/PV+ ependymal cells found in younger mice diminished in the LV-wall adhesions throughout aging. We found that periventricular PV-immunofluorescence showed positive correlation to the grade of LV stenosis in nonaged mice (<10-month-old), and that the extent of LV-wall adhesions and LV stenosis was significantly lower in mid- aged (>10-month-old) PV-knock out (PV-KO) mice. This suggests an involvement of PV+ ependymal cells in aging-associated ventricle stenosis. Additionally, we observed a time-shift in microglial activation in the LV-wall adhesions between age-grouped PV- KO and wild-type mice, suggesting a delay in microglial activation when PV is absent from ependymal cells. Our findings implicate that compromised ependymal cells of the adhering ependymal layers upregulate PV and display phenotype shift to “reactive” ependymal cells in aging-related ventricle stenosis; moreover, they also contribute to the progression of LV-wall fusion associated with a decline of the affected SVZ-stem cell niche in aged mice. application/pdf https://folia.unifr.ch/global/documents/305989 https://folia.unifr.ch/documents/305989/files/cel_pee.pdf eng info:eu-repo/semantics/altIdentifier/doi/10.1002/cne.24276 info:eu-repo/semantics/openAccess License undefined Journal of Comparative Neurology. - 2017, vol. 525, no. 15, p. 3266–3285 Aging Ependymal cell Lateral ventricle Parvalbumin Ventricle stenosis RRID:AB_10000344 RRID:AB_2665495 RRID:AB_2315304 RRID:AB_2620025 RRID:AB_1555288 RRID:AB_221569 RRII info:eu-repo/classification/udc/57 Parvalbumin-expressing ependymal cells in rostral lateral ventricle wall adhesions contribute to aging-related ventricle stenosis in mice http://purl.org/coar/resource_type/c_6501