| 1. |
- Glavaski-Joksimovic, Aleksandra, et al.
(författare)
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Survival, migration, and differentiation of Sox1-GFP embryonic stem cells in coculture with an auditory brainstem slice preparation
- 2008
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Ingår i: Cloning and Stem Cells. - : Mary Ann Liebert. - 1536-2302 .- 1557-7457. ; 10:1, s. 75-87
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Tidskriftsartikel (refereegranskat)abstract
- The poor regeneration capability of the mammalian hearing organ has initiated different approaches to enhance its functionality after injury. To evaluate a potential neuronal repair paradigm in the inner ear and cochlear nerve we have previously used embryonic neuronal tissue and stem cells for implantation in vivo and in vitro. At present, we have used in vitro techniques to study the survival and differentiation of Sox1-green fluorescent protein (GFP) mouse embryonic stem (ES) cells as a monoculture or as a coculture with rat auditory brainstem slices. For the coculture, 300 mu m-thick brainstem slices encompassing the cochlear nucleus and cochlear nerve were prepared from postnatal SD rats. The. slices were propagated using the membrane interface method and the cochlear nuclei were prelabeled with DiI. After some days in culture a suspension of Sox1 cells was deposited next to the brainstem slice. Following. deposition Sox1 cells migrated toward the brainstem and onto the cochlear nucleus. GFP was not detectable in undifferentiated ES cells but became evident during neural differentiation.. Up to 2 weeks after transplantation the cocultures were fixed. The undifferentiated cells were evaluated with antibodies against progenitor cells whereas the differentiated cells were determined with neuronal and glial markers. The morphological and immunohistochemical data indicated that Sox1 cells in monoculture differentiated into a higher percentage of glial cells than neurons. However, when a coculture was used a significantly lower percentage of Sox1 cells differentiated into glial cells. The results demonstrate that a coculture of Sox1 cells and auditory brainstem present a useful model to study stem cell differentiation.
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| 2. |
- Kaiser, Andreas, et al.
(författare)
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Brain stern slice conditioned medium contains endogenous BDNF and GDNF that affect neural crest boundary cap cells in co-culture
- 2014
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Ingår i: Brain Research. - : Elsevier. - 0006-8993 .- 1872-6240. ; 1566, s. 12-23
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Tidskriftsartikel (refereegranskat)abstract
- Conditioned medium (CM), made by collecting medium after a few days in cell culture and then re-using it to further stimulate other cells, is a known experimental concept since the 1950s. Our group has explored this technique to stimulate the performance of cells in culture in general, and to evaluate stem- and progenitor cell aptitude for auditory nerve repair enhancement in particular. As compared to other mediums, all primary endpoints in our published experimental settings have weighed in favor of conditioned culture medium, where we have shown that conditioned culture medium has a stimulatory effect on cell survival. In order to explore the reasons for this improved survival we set out to analyze the conditioned culture medium. We utilized ELISA kits to investigate whether brain stem (BS) slice CM contains any significant amounts of brain-derived neurotrophic factor (BDNF) and glial cell derived neurotrophic factor (GDNF). We further looked for a donor cell with progenitor characteristics that would be receptive to BDNF and GDNF. We chose the well-documented boundary cap (BC) progenitor cells to be tested in our in vitro co-culture setting together with cochlear nucleus (CN) of the BS. The results show that BS CM contains BDNF and GDNF and that survival of BC cells, as well as BC cell differentiation into neurons, were enhanced when BS CM were used. Altogether, we conclude that BC cells transplanted into a BDNF and GDNF rich environment could be suitable for treatment of a traumatized or degenerated auditory nerve.
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| 3. |
- Thonabulsombat, Charoensri, et al.
(författare)
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Implanted embryonic sensory neurons project axons toward adult auditory brainstem neurons in roller drum and Stoppini co-cultures
- 2007
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Ingår i: Brain Research. - : Elsevier. - 0006-8993 .- 1872-6240. ; 1170, s. 48-58
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Tidskriftsartikel (refereegranskat)abstract
- Previously we have shown in vivo the survival, migration and integration of embryonic dorsal root ganglion (DRG) neurons that were grafted into the inner ear and peripheral auditory nervous system. In order to evaluate relevant factors determining integration of sensory neurons further into the central auditory nervous system, complementary in vitro techniques are necessary. The advantages of in vitro systems are that a large number of factors including various grafts and different conditions can be efficiently examined for. Hence, we co-cultured 300 mu m thick postnatal rat brainstem slices containing the cochlear nucleus including the central part of the 8th cranial nerve with mouse embryonic DRG neurons. The organotypic co-cultures were either grown on coverslips using the roller drum method described by Gahwiler or on membranes according to the interface method described by Stoppini. Neurons in the cochlear nucleus were labeled, with DiI. The results demonstrate that (1) brainstem slices survive for up to 5 weeks in culture, and that (2) co-cultures of embryonic sensory neurons and brainstern show a high degree of neuronal survival, and that (3) survival and axonal outgrowth from the implanted embryonic neurons are dependant on the presence of the brainstern slice rather than on exogenous NGF and that (4) implanted embryonic neurons send axons toward neurons in the cochlear nucleus. (c) 2007 Published by Elsevier B.V.
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