Altered adult neurogenesis and gliogenesis in patients with mesial temporal lobe epilepsy.

The hippocampus is the most common seizure focus in people. In the hippocampus, aberrant neurogenesis plays a critical role in the initiation and progression of epilepsy in rodent models, but it is unknown whether this also holds true in humans. To address this question, we used immunofluorescence on control healthy hippocampus and surgical resections from mesial temporal lobe epilepsy (MTLE), plus neural stem-cell cultures and multi-electrode recordings of ex vivo hippocampal slices. We found that a longer duration of epilepsy is associated with a sharp decline in neuronal production and persistent numbers in astrogenesis. Further, immature neurons in MTLE are mostly inactive, and are not observed in cases with local epileptiform-like activity. However, immature astroglia are present in every MTLE case and their location and activity are dependent on epileptiform-like activity. Immature astroglia, rather than newborn neurons, therefore represent a potential target to continually modulate adult human neuronal hyperactivity.

The Presence of Neural Stem Cells and Changes in Stem Cell-Like Activity With Age in Mouse Spiral Ganglion Cells In Vivo and In Vitro.

OBJECTIVES: Spiral ganglion neurons (SGNs) include potential endogenous progenitor populations for the regeneration of the peripheral auditory system. However, whether these populations are present in adult mice is largely unknown. We examined the presence and characteristics of SGN-neural stem cells (NSCs) in mice as a function of age. METHODS: The expression of Nestin and Ki67 was examined in sequentially dissected cochlear modiolar tissues from mice of different ages (from postnatal day to 24 weeks) and the sphere-forming populations from the SGNs were isolated and differentiated into different cell types. RESULTS: There were significant decreases in Nestin and Ki67 double-positive mitotic progenitor cells in vivo with increasing mouse age. The SGNs formed spheres exhibiting self-renewing activity and multipotent capacity, which were seen in NSCs and were capable of differentiating into neuron and glial cell types. The SGN spheres derived from mice at an early age (postnatal day or 2 weeks) contained more mitotic stem cells than those from mice at a late age. CONCLUSION: Our findings showed the presence of self-renewing and proliferative subtypes of SGN-NSCs which might serve as a promising source for the regeneration of auditory neurons even in adult mice.

CD66 and CD49f expressing cells are associated with distinct neoplastic phenotypes and progression in human cervical cancer.

BACKGROUND: In this study, building on our recent work identifying a subset of CD66+ve cells with distinctive tumourigenic properties in human cervical cancers, we examine patterns of expression and function of these cells; to generate insights into the process of metastasis. METHODS: Our broad approach in this study has been to compare the expression and function of two subsets marked by CD66 and CD49f. We use a combination of histopathology, immunostaining and flow cytometry, functional analysis of an established cervical cancer cell line and a retrospective analysis of a cohort of cervical cancer. RESULTS: We noted CD66 expression associated with clusters of cells which are spindle shaped, SMA+ve, podoplanin+ve, phalloidin high, fibronectin high, plakoglobin low, ki67-ve and CK10+ve at the migratory phase along with features of partial EMT. Further, TGFß1 a well known regulator of EMT, positively correlated with CD66 expression. The additional CD49f+ve subset at the leading invading front of migration was SMA-ve, phalloidin low, fibronectin low, plakoglobin high, Ki67+ve and CK14+ve. These data are consistent with a role for CD66 cells in metastatic invasion with a collective cell migration process co-opting the CD49f subset. Our retrospective analysis of a cohort is consistent with a role for CD66 in metastasis. However, the broad analysis of CD66, CD49f and TGFß1 expression with patterns of overall survival points to a possible protective effect particularly for local recurrences. Hence, future studies focussing on potential heterogeneity within the CD66 subset along with the possible role of isoforms and intra-cellular roles would be essential.

CD66+ cells in cervical precancers are partially differentiated progenitors with neoplastic traits.

Cervical cancers, a malignancy associated with oncogenic papilloma viruses, remain a major disease burden in the absence of effective implementation of preventive strategies. CD66(+) cells have previously been identified as a tumor-propagating subset in cervical cancers. We investigated the existence, differentiation state, and neoplastic potential of CD66(+) cells in a precancer cell line harboring HPV31b episomes. The gene expression profile of CD66(high) cells overlaps with differentiated keratinocytes, neoplastic mesenchymal transition, cells of the squamocolumnar junction, and cervical cancer cell line-derived spheroids. There is elevated expression of DNMT1, Notch1, and the viral gene product E1⁁E4 in CD66(high) cells. Thus, CD66(high) cells, in the absence of differentiating signals, express higher levels of key regulators of keratinocytes stemness, differentiation, and the viral life cycle, respectively. We also find a striking association of neoplastic traits, including migration, invasion, and colony formation, in soft agar with CD66(high) cells. These properties and a distinct G2-M-enriched cell-cycle profile are conserved in cells from cervical cancers. Principally, using a precancerous cell line, we propose that CD66(high) cells have an intermediate differentiation state, with a cellular milieu connected with both viral replication and neoplastic potential, and validate some key features in precancer lesions. Such pathophysiologically relevant systems for defining cellular changes in the early phases of the disease process provide both mechanistic insight and potential therapeutic strategies. Collectively, our data provide a rationale for exploring novel therapeutic targets in CD66(+) subsets during cancer progression.